OF  THK 


UNIVERSITY  OF  CALIFORNIA. 

GIFT   OK* 

Mrs.  SARAH  P.  WALS WORTH. 

Received  October,  1894. 
Accessions  No.S^^jf1^.      Class  No.  . 


GKAHAI   LECTUKES: 

ON    THE 

POWER,    WISDOM,    AND    GOODNESS 

OF    GOD, 

AS  MANIFESTED  IN  HIS  WOKKS, 
VOLUME   III. 

PUBLISHED    BY 

THE   BROOKLYN   INSTITUTE. 


BEHGION  AND  CSEIISTEY; 


OR, 


PROOFS  OP  GOD'S  PLAN  IN  THE  ATMOSPHERE 
AND  ITS  ELEMENTS. 


TEN    LECTURES 

DELIVERED  AT  THE  BROOKLYN  INSTITUTE,  BROOKLYN,  N.  Y, 

ON  THE   GRAHAM  .FOUNDATION. 


BY 

JOSIAH   P.   COOKE,  JR., 

ERVING    PROCESSOR    OF    CHEMISTRY    AND    MINERALOGY 
IN   HARVARD   UNIVERSITY. 


"Duo  sunt  quse  in  cognitionem  Dei  ducunt ;  Creatura  et  Scriptura." 

ST.  AUGUSTINE. 


NEW    YORK: 
CHARLES    SCRIBNER,   124   GRAND   STREET. 

1864. 


Entered  according  to  Act  of  Congress,  in  the  year  1864,  by 
PETER    G.    TAYLOR, 

President  of  the  Brooklyn  Institute, 

in  the  Clerk's  Office  of  the  District  Court  of  the  United  States  for  the  Southern  District  of 
New  York. 


UNIVERSITY  PRESS: 

WELCH,  BIGELOW,  AND  COMPANY, 

CAMBRIDGE. 


1  ',  TO' 

MY    FATHER, 

THIS   BOOK 

18   AFFECTIONATELY   AND    GRATEFULLY 
DEDICATED. 


PKEFACE. 


THE  Lectures  now  published  were  first  delivered 
before  the  Brooklyn  Institute  on  Sunday  evenings 
of  January  and  February,  1861,  and  the  larger 
part  of  them  were  subsequently  repeated,  during 
the  same  winter,  before  the  Lowell  Institute  in 
Boston,  and  before  the  Mechanics'  Association  of 
Lowell.  The  progress  of  science  since  that  time 
has  rendered  necessary  many  additions,  and  in  re- 
vising the  Lectures  for  publication,  the  material 
has  been  thus  so  greatly  increased  that  what  was 
originally  prepared  and  delivered  as  six  Lectures  is 
now  distributed  over  ten.  At  the  time  when  the 
Lectures  were  written,  Mr.  Darwin's  book  on  the 
Origin  of  Species,  then  recently  published,  was  ex- 
citing great  attention,  and  was  thought  by  many 
to  have  an  injurious  bearing  on  the  argument 
for  design.  It  was,  therefore,  made  the  chief  aim 
of  these  Lectures  to  show  that  there  is  abundant 
evidence  of  design  in  the  properties  of  the  chemi- 
cal elements  alone,  and  hence  that  the  great  argu- 


Vlil  PREFACE. 

ment  of  Natural  Theology  rests  upon  a  basis  which 
no  theories  of  organic  development  can  shake.  In 
illustrating  his  subject,  the  author  has  used  freely 
all  the  materials  at  his  command,  and  if,  in  any 
case,  he  has  failed  to  give  due  acknowledgment,  it 
has  been  because  by  long  dwelling  on  the  subject 
the  thoughts  of  others  have  become  blended  with 
his  own.  He  would  here  acknowledge  his  repeated 
indebtedness  to  Professor  Guyot's  work  on  "Earth 
and  Man,"  to  Professor  Faraday's  published  Courses 
of  Elementary  Lectures,  and  to  Professor  Tyn- 
dall's  Lectures  on  "Heat  considered  as  a  Mode  of 
Motion."  He  would  also  express  his  especial  obli- 
gations to  the  author  of  "  In  Memoriam,"  in  whose 
verses  he  has  discovered  a  truer  appreciation  of 
the  difficulties  which  beset  the  questions  discussed 
in  this  volume,  than  he  has  ever  found  in  the  phi- 
losophy of  the  schools. 

CAMBRIDGE,  May  3d,  1864. 


CONTENTS. 


I.  STATEMENT  OF  THE  CASE       .        .        .  .         1-15 

II.  TESTIMONY  OF  THE  ATMOSPHERE        .        .  16-72 

III.  TESTIMONY  OF  OXYGEN          .        .        .  .  73-124 

IV.  TESTIMONY  OF  WATER      ....  125-170 
V.  TESTIMONY  OF  CARBONIC  ACID       .        .  .     171-211 

VI.  TESTIMONY  OF  NITROGEN  ....  212-238 

VII.  ARGUMENT  FROM  SPECIAL  ADAPTATIONS  .    239-266 

VIII.  ARGUMENT  FROM  GENERAL  PLAN       .        .  267-341 

IX.  NECESSARY   LIMITATIONS    OF    SCIENTIFIC  AND 

KELIGIOUS  THOUGHT  341-348 


GRAHAM    LECTURES. 

RELIGION   AND    CHEMISTRY 


LECTUEE    I. 

STATEMENT  OF  THE  CASE. TESTIMONY  OF  THE  ATMOSPHERE. 

THE  time  has  been  when  the  Christian  Church 
was  an  active  antagonist  of  physical  science; 
when  the  whole  hierarchy  of  Eome  unit-  The  relation  of 
ed  to  condemn  its  results  and  to  resist  physic^sc^ 
its  progress;  when  the  immediate  reward  ence" 
of  great  discoveries  was  obloquy  and  persecution. 
But  all  this  has  passed.  The  age  of  dogmatism 
has  gone,  and  an  age  of  general  scepticism  has 
succeeded.  The  power  of  traditional  authority  has 
given  place  to  the  power  of  ideas,  and  physical 
science,  which  before  hardly  dared  to  assert  its 
birthright,  and  could  even  be  forced  to  recant,  on 
its  knees,  its  demonstrated  truths,  has  now  become 
one  of  the  rulers  of  society.  By  its  rapid  growth, 
by  its  conquests  over  brute  matter,  and  by  its 
wonderful  revelations,  it  has  deservedly  gained  the 
highest  respect  of  man,  while  by  multiplying  and 
diffusing  the  comforts  of  life  it  has  become  his 


2  RELIGION   AND    CHEMISTRY.  [LECT.  I. 

acknowledged  friend.  Every  effort  is  now  made 
to  further  its  progress.  Its  great  discoveries  win 
the  applause  of  nations,  and  its  fortunate  students 
are  remembered  when  the  princes  and  nobles  of 
the  earth  are  forgotten. 

All  this  is  well.  But  unfortunately,  elated  by 
his  success,  the  stripling  has  been  at  times  proud 
and  arrogant,  usurping  authority  not  his  due.  For- 
getting his  early  faith,  he  has  approached  with 
irreverent  thoughts  the  holy  temple  of  our  relig- 
ion, and,  not  content  to  worship  in  the  outer  court, 
has  dared  to  penetrate  into  the  very  Holy  of 
Holies,  and  apply  his  material  tests  even  to  the 
vessels  of  the  altar.  No  wonder  that  the  Church 
should  become  alarmed,  that  many  of  her  best  men, 
holding  fast  to  the  sacred  dogmas  of  our  religion 
as  the  only  sure  anchor  of  their  faith  in  this  world, 
and  their  sole  ground  of  hope  for  the  next,  should 
join  in  a  general  cry  against  the  whole  tendency 
of  science  and  its  results. 

But  this  is  a  great  mistake.  Judging  of  the 
real  character  of  physical  science  from  the  pre- 
tensions of  a  few,  and  not  possessing  the  power 
or  opportunity  of  investigating  for  themselves, 
these  good  men  are  unnecessarily  alarmed :  the 
phantom  they  fear  is  purely  of  their  own  crea- 
tion, and,  could  they  but  know  the  whole  truth, 
they  themselves  would,  see  that  to  ignore  the 
well-established  results  of  science,  and  to  denounce 
its  legitimate  tendency,  is  a  policy  as  short-sighted 
as  it  is  illiberal  and  unchristian. 


LECT.  I]  STATEMENT   OP   THE   CASE.  3 

Fortunately,  such  fearful  souls  constitute  but  a 
small  party  in  the  Christian  Church.  There  is  a 
far  nobler  and  more  courageous  faith  The  attitude  of 
than  theirs,  —  a  faith  so  strong  in  its  *  brave  cims- 

tian  faith. 

convictions  that  it  fears  no  criticism, 
however  searching,  and  no  scientific  analysis,  how- 
ever rigorous  it  may  be,  —  a  faith  which  finds  in 
the  Bible,  not  a  series  of  dead  formulas,  but  a 
mass  of  living  truth,  —  a  faith  which  really  be- 
lieves that  the  God  of  nature  is  the  God  of  grace, 
and  that  man  was  created  in  the  image  of  this 
one  and  only  God,  —  a  faith  which  wells  up  from 
the  depths  of  the  soul,  which  speaks  because  it 
believes,  which  believes  because  it  feels,  —  a  faith 
whose  sources  are  as  hidden  as  those  of  the  foun- 
tain, but  whose  reality  is  as  living  as  the  verdant 
landscape  which  the  fountain  waters. 

It  is  the  men  with  a  faith  like  this  who  are 
the  really  brave  Christians.  They  are  not  alarmed 
at  the  apparent  contradictions  between  science 
and  revelation.  By  the  very  imperfections  of 
their  own  faculties,  which  they  so  keenly  feel^ 
they  have  been  taught  that  mysteries  exist;  nay, 
they  find  in  these  very  mysteries  the  strongest 
bulwarks  of  their  faith ;  for  they  feel,  with  Eobert 
Hall,  that  "  a  religion  without  its  mysteries  would 
be  a  temple  without  its  God."  They  are  fully 
assured  that  our  minds  were  framed  after  the 
likeness  of  their  Divine  original,  in  order  that 
we,  creatures  of  the  dust  though  we  are,  might 
nevertheless  in  our  feeble  measure  comprehend 


4  RELIGION   AND    CHEMISTRY.  [LECT.  I. 

God's  workmanship  and  sympathize  with  his  di- 
vine thoughts  5  and  they  reject  as  absurd  the  doc- 
trine that  man,  thus  created  an  intelligent  and 
sympathizing  observer  of  God's  universe,  should 
have  been  permitted,  in  the  legitimate  exercise 
of  the  very  powers  which  God  has  given  him,  to 
build  up  a  connected  system  of  science  in  direct 
contradiction  with  those  higher  and  spiritual  truths 
which  the  Father  has  been  mercifully  pleased  to 
reveal  to  his  sinning  children  through  his  prophets 
and  his  Son. 

May  the  foundation  of  these  lectures  ever  stand 
as  a  monument  of  this  brave  Christian  faith.  He 
who  provided  in  his  last  testament  that  the  wis- 
dom, power,  and  goodness  of  his  God  should  at 
short  intervals  be  illustrated  in  this  place  from 
the  varied  stores  of  knowledge  which  the  inves- 
tigator of  nature  might  collect,  could  not  have 
feared  that  there  was  any  essential  contradiction 
between  science  and  revelation.  On  the  contrary, 
he  must  have  felt  that  science  would  become  the 
great  champion  of  the  Christian  faith;  and  may 
the  result  fully  prove  his  wisdom  and  his  fore- 
sight. 

It  will  be  my  object,  in  the  present  course  of 
lectures,  to  aid  in  carrying  out  the  noble  pur- 
The  whole  ma-  Poses  °f  the  founder  by  developing  be- 
teriai  creation  fore  yOU  ^e  illustrations  of  the  wisdom, 

illustrates 

God's  attri-      goodness,  and  power  of  God,  which  have 

been   discovered   in   the    constitution  of 

matter.     The  material  of  this  universe,  by  which 


LKCT.I.]  STATEMENT   OF   THE   CASE.  5 

we  are  surrounded  and  in  which  we  live  and 
move,  is  full  of  the  evidences  of  these  attri- 
butes of  the  Creator.  They  crowd  upon  us  from 
every  side.  Wherever  we  turn  our  eyes  there 
we  read  them,  on  the  blue  dome  of  heaven,  and 
on  the  gorgeous  cloud-turrets  of  the  western  sky ; 
they  are  inscribed  on  the  rocky  cliffs  which  re- 
cord the  memory  of  long-buried  ages,  and  on  the 
green  'sods  which  cover  the  last-made  grave  ;  they 
are  heard  in  the  crackling  of  the  conflagration  no 
less  than  in  the  roaring  of  the  tempest,  in  the 
pattering  of  the  rain-drop  as  well  as  in  the  roll- 
ing of  the  thunder. 

u  The  heavens  declare  the  glory  of  God,  and 
"the  firmament  showeth  his  handy  work.  Day 
"  unto  day  uttereth  speech,  and  night  unto  night 
"  showeth  knowledge.  There  is  no  speech  nor  lan- 
"  guage  where  their  voice  is  not  heard.  Their  line 
"  is  gone  out  through  all  the  earth,  and  their  words 
"to  the  end  of  the  world." 

It  is  the  privilege  and  duty  of  the  student  of 
nature  to  interpret  the  characters  in  which  these 
evidences  are  written,  and  the  language  which 
nature  speaks;  but  the  best  translation  gives  only 
an  inadequate  idea  even  of  a  work  of  human 
genius,  and  far  less  can  my  imperfect  rendering 
convey  to  you  the  full  force  of  that  impression 
which  the  devout  student  receives  while  studying 
the  perfect  works  of  God. 

The  illustrations  of  the  attributes  of  God,  which 
may  be  drawn  from  the  constitution  of  matter,  are 


Two  classes 
illustrations. 


6  KELIGION   AND    CHEMISTRY.  [Lacr.  I. 

conveniently  divided  into  two  classes,  —  first,  those 
of  which  appear  in  the  adaptation  of  vari- 
ous means  to  a  particular  end,  and, 
second,  those  which  are  to  be  found  in  the  unity 
of  plan  according  to  which  the  whole  frame  of 
nature  has  been  constructed.  The  first  class  are 
exhibited  by  the  properties  of  matter,  the  second 
by  the  so-called  physical  laws  and  forces. 

There  are  probably  no  forms  of  matter  in  which, 
even  with  our  present  imperfect  knowledge,  a  com- 
bination of  means  conspiring  to  some  beneficent 
end  cannot  be  traced ;  but  such  adaptations  are 
more  especially  to  be  seen  in  the  properties  of 
those  substances  which  are  the  most  intimately 
associated  with  man,  and  on  which  his  existence 
and  happiness  depend.  We  shall  not,  therefore,  be 
obliged  to  search  the  recondite  facts  of  science,  or 
to  investigate  the  rarities  of  nature,  to  find  our 
illustrations  of  the  Divine  attributes;  they  lie  all 
around  us,  in  the  air  we  breathe,  in  the  water  we 
drink,  and  in  the  coal  we  burn;  and  what  more 
convincing  evidence  could  we  have  of  the  benefi- 
cence of  our  Heavenly  Father  than  the  very  fact 
that  these  familiar  substances  are  of  all  others 
most  vocal  with  his  praise? 

In  following  out,  then,  the  order  which  seems  to 
be  so  obviously  indicated  by  the  nature  of  the 
The  plan  of  this  case'  ^  ^aH  as^  J^U9  in  the  first  place,  to 
course  of  lee-  study  with  me  the  physical  condition  of 
our  atmosphere,  and  the  properties  of  the 
various  materials  of  which  it  consists;  and  I  am 


LECT.  L]  STATEMENT   OF   THE   CASE.  7 

sure  we  shall  not  fail  to  find  in  one  and  all  abun- 
dant evidence  of  the  wisdom,  goodness,  and  power 
of  God.  Having  thus  made  you  acquainted  with 
some  of  the  more  important  scientific  facts  re- 
quired for  my  argument,  I  shall  next  direct  your 
attention  to  those  grander  demonstrations  of  God's 
wisdom '  and  power  which  appear  in  the  great  laws 
and  forces,  by  which  the  whole  material  universe 
is  upheld,  and  lastly  an  examination  of  the  relative 
limits  of  scientific  and  religious  thought  will  form 
an  appropriate  termination  for  the  course. 

The  argument  from  special  adaptations  which  lies 
at  the  basis  of  all  works  on  natural  theology  is 
admirably  condensed  by  Dugald  Stewart  „, 

*  The  argument 

into  two  simple  propositions.  The  one  from  special 
is,  "  that  everything  which  begins  to  ex- 
ist must  have  a  cause";  the  other,  "that  a  com- 
bination of  means  conspiring  to  a  particular  end 
implies  intelligence."  To  these  might  be  added  the 
two  equally  clear  propositions  stated  by  Dr.  Eeid : 
first,  "that  design  may  be  traced  from  its  effects"; 
second,  "  that  there  are  evidences  of  design  in  the 
universe."  I  do  not  intend  to  discuss  at  length 
the  logical  validity  of  this  argument,  or  the  gen- 
eral value  of  analogical  reasoning  which  it  implies. 
Such  discussions  belong  particularly  to  the  prov- 
ince of  metaphysics,  and  I  willingly  leave  them 
to  abler  hands.  It  will  be  my  chief  object  in 
these  lectures  to  bring  to  your  notice  a  few  of  the 
numberless  indications  of  adaptation  in  the  mate- 
rials of  our  atmosphere,  assuming  for  the  present 


8  RELIGION   AND    CHEMISTRY.  [LECT.  I. 

that  these  adaptations  are  evidences  of  design,  and 
therefore  evidences  of  the  existence  of  a  personal 
God,  infinite  in  wisdom,  absolute  in  power.  When 
we  have  thus  become  acquainted  with  some  of  the 
facts  on  which  the  argument  rests,  we  may  then 
profitably  consider  the  validity  of  the  reasoning,  at 
least  so  far  as  to  weigh  the  objections,  which  mod- 
ern materialism  has  urged  against  it. 

I  am  well  aware  that  great  prejudice  is  enter- 
tained in  many  religious  minds  against  the  whole 

scheme  of  natural  theology,  originating 
against  natural  in  a  vague  idea  that  its  study  is  in  some 

measure  unfavorable  to  the  growth  of 
Christian  faith.  That  such  an  impression  should 
be  produced  by  a  class  of  modern  writers,  who 
think  to  supersede  Christianity  by  a  sort  of  pan- 
theistic naturalism,  is  not  surprising ;  but  certainly 
natural  theology  is  no  more  chargeable  with  the 
presumption  of  such  speculations  than  is  Christi- 
anity with  the  excesses  of  Jesuitism.  Let  me  not 
be  misunderstood.  I  have  no  desire  to  press  the 
argument  of  natural  theology  too  far. 

For  myself,  I  believe  that  the  facts  of  human 
nature  themselves  all  tend  to  prove  that  a  divine 
Natural  theoi-  revelation  is  the  only  legitimate  basis  for 

a  svstem  °f  religion,  and  that  an  histor- 

iCal  faith  based  on  a  supernatural  revela- 
tion is  the  only  religion  possible  for  imperfect 
humanity.  Indeed,  I  am  led  to  think  we  find  evi- 
dence of  the  goodness  of  our  Heavenly  Father  in 
the  very  circumstance  that  the  foundations  of  all 


I.]  STATEMENT   OF   THE   CASE.  9 

knowledge  have  been  laid  in  such  obscurity  that 
no  unaided  human  intellect  can  wholly  dispel  the 
cloud  which  hides  the  Creator  from  our  sight, — 

"  To  feel,  although  no  tongue  can  prove, 
That  every  cloud  that  spreads  above 
And  veileth  love,  itself  is  love." 

This  very  obscurity  humbles  the  pride  of  human 
learning,  and  raises  its  constant  warning  against 
that  intellectual  idolatry  which  would  substitute 
its  shallow  philosophy  for  the  simple  truth  as  it 
is  in  Jesus.  The  Bible  once  received,  science  can 
furnish  abundant  illustrations  of  the  attributes  of 
the  Being  therein  revealed ;  but  even  with  all 
the  illumination  which  has  been  the  immediate 
or  secondary  result  of  Christianity,  man  is  hope- 
less without  its  authority,  and  I  would  not  give 
the  slightest  shadow  of  support  to  that  irreverent 
presumption  which,  guided  by  what  it  calls  the 
unaided  light  of  nature,  would  construct  a  system 
of  religion  out  of  passions,  intuitions,  and  I  know 
not  what  absurdity. 

But  still  it  must  be  remembered  that  the  Chris- 
tian revelation  does  not  prove  the  existence  of 
God ;  on  the  contrary,  it  is  based  on  a  Natural  theoi- 
belief  in  his  being  that  already  exists  in  SofS-1 
the  mind  of  man.  The  Bible  opens  with  tianity- 
this  assumption.  The  first  line  asserts  that 

u  In  the  beginning  God  created  the  heaven  and 
"the  earth." 

And  the  Hebrew  name  of  God,  Jehovah  (lam  that 
Iam\  is  itself  a  declaration  of  his  self-existent  being. 


10  RELIGION   AND    CHEMISTRY.  [LECT.  I. 

With  all  men  a  belief  in  some  Almighty  Power 
overshadowing  their  being  grows  up  spontaneously 
in  the  heart,  they  know  not  how ;  but  the  edu- 
cated and  the  intelligent  seek  further  to  find  its 
logical  grounds  in  the  evidences  of  nature. 

Here,  then,  is  the  first  great  office  of  natural 
theology.  It  furnishes  the  logical  basis  on  which 
the  whole  scheme  of  revealed  religion  given  us 
in  the  Bible  rests. 

I  have  no  desire  to  over-estimate  the  importance 
of  my  subject.  For  myself,  I  believe,  with  Paley 
and  the  other  eminent  writers  of  the  same  class, 
that  the  fundamental  truths  of  our  religion  can 
be  inferred  from  the  constitution  of  the  human 
mind  and  from  the  course  of  nature  with  as  much 
certainty  as  analogical  reasoning  can  ever  give. 
But  still  I  know  that  the  evidence  is  not  demon- 
strative and  not  likely  to  convince  the  sceptic; 
for  in  the  last  analysis  it  rests  on  certain  assump- 
tions which  he  will  not  admit.  And  it  is  in  vain 
to  urge  that  these  assumptions  are  really  intui- 
tive truths  and  tacitly  admitted  by  the  whole 
human  race ;  for  he  easily  replies,  that  they  are 
not  intuitive  to  his  mind. 

Nevertheless,  the  evidences  of  God  in  nature 
are  the  only  proof  we  have  or  can  have  of  his 
existence,  and  they  are  therefore  the  only  logical 
basis  of  the  Christian  revelation.  Nature  and  rev- 
elation are  parts  of  one  and  the  same  system,  and, 
however  much  our  prejudices  may  obscure  the 
fact,  Christianity  rests  on  natural  religion,  and 


LECT.I.]  STATEMENT   OF  THE   CASE.  11 

cannot  be  logically  defended  if  the  authority  of 
the  last  is  denied.* 

But  however  great  the  value  of  natural  theol- 
ogy, considered  as  the  basis  on  which  revelation 
rests,  this  is  not  its  only  or  most  impor-  „ 

•*  *  Natural  theol- 

tant  office.     In  the  present  age  of  the  °sy  confirms 
world  it  confers  a  still  more  inestimable  the  truths  of 
benefit  on  mankind  by  confirming,  illus-  r< 
trating,  and  enforcing  the  admitted  truths  of  rev- 
elation. 

If  it  be  asked  of  what  value  are  further  illus- 
trations of  admitted  truths,  I  answer,  that  there 
is  an  important  class  of  nominal  Christians  who 
are  more  open  to  impressions  from  the  study  of 
nature  than  to  direct  appeals  to  the  heart.  It 
is  true  that  the  great  mass  of  mankind  must  be 
Christianized,  if  at  all,  through  the  affections  and 
by  the  hard  discipline  of  sorrow;  but  there  are 
some  who,  not  yet  tried  in  the  fiery  furnace  of 
affliction,  have  first  felt  their  Father's  hand  and 
recognized  his  love'  while  contemplating  his  works. 
I  do  not  say  that  persons  so  touched  are  already 
Christians,  but  I  do  say  that  the  first  step  has 
been  taken,  and  that  is  a  great  deal.  It  may 
require  many  years  of  sad  experience  and  many 
a  bitter  pang  of  disappointment  before^  they  come 
to  kneel  humbly  at  their  Saviour's  feet ;  but,  like 
the  great  Apostle,  they  will  always  look  back  to 
the  time  when  the  Divine  presence  first  visibly 

*  See  a  recent  work  by  the  Kev.  A.  P.  Peabody,  D.  D.,  entitled, 
"  Christianity  the  Religion  of  Nature,"  for  a  development  of  this  idea. 


12  RELIGION  AND    CHEMISTRY.  [LECT.  I. 

shone  before  them  as  the  turning  period  of  their 
life. 

While,  therefore,  I  should  be  the  first  to  condemn 
that  hollow  naturalism  which  would  substitute  a 
importance  of  system  of  natural  theism  for  the  simple 
this  office.  doctrines  of  the  Bible,  I  must  also  depre- 
cate that  prejudice  which  prevents  many  clergy- 
men, through  fear  of  this  tendency  of  the  age,  from 
availing  themselves  of  the  aid  of  science  in  enfor- 
cing the  fundamental  truths  of  our  religion.  I  as- 
sure them  they  thus  neglect  a  most  important 
means  of  influence  over  educated  and  thinking 
men,  —  a  means  of  influence  always  important,  but 
never  more  so  than  in  an  age  which  is  marked 
by  its  cultivation  of  practical  science,  and  in  a 
country  where  so  large  a  portion  of  the  active 
energy  of  the  community  has  taken  this  practical 
direction.  The  danger  of  our  time  is  not  so  much 
a  philosophical  scepticism  as  a  practical  materialism. 
The  fear  is,  not  that  men  should  reason  themselves 
into  unbelief,  but  that,  spending  their  whole  lives 
in  developing  the  powers  of  nature,  they  should 
practically  worship  the  dead  matter,  rather  than 
the  living  God.  If,  however,  you  can  make  such 
persons  feel  that  the  material  is  but  a  form  of  the 
spiritual,  and  that  in  fact  the  spiritual  is  nowhere 
more  manifest  than  in  those  very  laws  and  forces 
which  they  so  much  idolize,  you  will  not  change, 
it  is  true,  the  tendency  of  the  age,  but  you  will 
ennoble  and  sanctify  it.  The  whole  material  uni- 
verse will  become  transfigured,  and  nature  will  no 


LECT.L]  STATEMENT    OF   THE   CASE.  13 

longer  be  seen  as  a  wonderful  mechanical  applica- 
tion of  blind  forces,  but  as  a  living  embodiment 
of  the  Eternal  One.  Nature-worship  may  continue, 
but  it  will  have  lost  its  idolatry ;  for  it  will  be 
no  longer  the  machine  that  is  worshipped,  but  that 
same  Living  Spirit  which  spoke  in  tones  of  thunder 
from  the  clouds  of  Sinai  and  in  accents  of  mercy  at 
the  baptism  of  Christ. 

I  know  it  is  said  that  nature  conceals  rather  than 
reveals  God,  and  in  a  certain  sense  it  is  undoubtedly 
true  that  He  is  hidden  from  us  behind  the  veil  of 
his  works  ;  but  since  it  is  permitted  to  man  by  the 
exercise  of  his  intelligence  to  lift  in  part  this  veil, 
it  is  certainly  the  duty,  as  it  should  be  the  privi- 
lege, of  the  ministers  of  religion  to  show  forth  the 
unspeakable  glory  which  lies  behind  these  material 
forms. 

But  why  multiply  arguments  when  we  have  the 
authority  of  the  Great  Teacher  himself,  who  fre- 
quently appealed  to  nature  to  illustrate  and  Example  of 
enforce  the  divine  truths  which  he  came  Christ> 
on  earth  to  reveal  ?  We  have  indeed  the  whole 
summary  of  Natural  Theology  in  His  simple  words. 

u  Wherefore,  if  God  so  clothe  the  grass  of  the 
u  field,  which  to-day  is,  and  to-morrow  is  cast  into 
"  the  oven,  shall  he  not  much  more  clothe  you,  0 
"ye  of  little  faith?" 

With,  then,  such  authority  as  this,  let  us  not  de- 
spise the  beginnings  because  they  are  not  the  end, 
or  undervalue  the  means  by  which  many  a  noble 
soul  has  been  led  to  the  foot  of  the  Cross. 


14  RELIGION   AND    CHEMISTRY.  [LECT.  I. 

Without  seeking,  therefore,  to  vindicate  further 
the  claims  of  my  subject,  I  will  at  once  enter  upon 
the  plan  already  proposed  for  this  course  of  lec- 
tures, and  will  first  ask  your  attention  to  the  illus- 
trations of  the  wisdom,  goodness,  and  power  of  God, 
which  may  be  discovered  in  the  constitution  of  our 
atmosphere.  In  endeavoring  to  carry  out  this  plan, 
I  shall  require  all  your  indulgence  and  all  your 
kind  forbearance.  From  the  very  nature  of  the 
case,  it  will  be  necessary  to  start  from  first  princi- 
ples, and  much  of  the  way  we  are  to  travel  together 
will  be  uninteresting  and  dull.  If,  however,  the  path 
shall  lead  us  to  the  summit  of  that  holy  mountain 
from  which  we  can  gain  a  clearer  vision  of  spiritual 
things,  we  shall  soon  forget  the  toil  and  difficulty 
of  the  ascent.  We  have  no  extravagant  expecta- 
tions of  the  result.  We  do  not  hope  to  convince 
the  sceptic,  or  to  arouse  the  indifferent  from  their 
practical  unbelief.  Our  only  hope  is,  —  and  this  we 
entertain  in  all  humility,  —  that,  by  pointing  out  a 
few  of  the  footprints  of  the  Creator  which  lie  thickly 
along  our  daily  path,  we  may  encourage  some  ear- 
nest student  toiling  forward  on  his  journey  of  life. 
May  God  grant  to  us  all  the  richest  blessings  of 
His  grace;  for  though  man  may  plant  and  water, 
He  only  giveth  the  increase. 

The  illustrations  of  the  attributes  of  God  pre- 
sented to  us  by  the  atmosphere  are  especially 
manifest  in  those  adaptations  of  properties  by 
which  it  has  been  made  to  subserve  the  welfare 
and  happiness  of  mankind.  Here,  however,  as 


LECT.L]  STATEMENT   OF   THE   CASE.  15 

always  in  the  study  of  nature,  we  must  be  careful 
to  avoid  the  error  of  considering  man  as 

IP-  A      AdaPtations  in 

the  sole  end  of  creation,  and  of  interpret-  the  atmosphere 


ing  all  phenomena  with  reference  to  him 
alone.    The  material  universe  is  the  mani- 

yni^nT 

festation  of  one  grand  creative  thought,  as 
comprehensive  in  the  diversity  of  the  parts,  as  it  is 
grand  in  the  unity  of  the  whole.  These  parts  have 
been  so  wondrously  joined  and  skilfully  wrought 
together,  that  each  is  linked  with  each,  and  one 
with  all.  In  this  Divine  economy  nothing  is  want- 
ing, nothing  is  superfluous,  and  what  seems  to  our 
feeble  vision  least  important  is  as  essential  to  com- 
plete the  unity  of  the  plan  as  our  own  glorious 
manhood  : 

"  Nothing  useless  is  or  low, 
Each  thing  in  its  place  is  best, 
And  what  seems  but  idle  show 
Strengthens  and  supports  the  rest." 

Amidst  all  this  wonderful  variety  in  unity,  man 
stands  the  culminating  glory  of  the  whole.  Made 
in  the  image  of  his  Creator,  and  but  "  a  little  lower 
than  the  angels,"  he  has  been  intrusted  with  do- 
minion and  power  over  all  the  brute  matter  which 
surrounds  him.  Through  the  long  ages  of  geologi- 
cal history  the  earth  was  preparing  for  his  dwelling, 
and  in  the  earliest  forms  of  animal  life  his  coming 
was  prefigured  and  foretold.  It  will  be  natural, 
therefore,  to  consider  the  adaptations  of  the  atmos- 
phere with  special  reference  to  him;  and  this  we 
may  do  legitimately,  without  losing  sight  of  the 


16  RELIGION   AND    CHEMISTRY.  [LECT.  I. 

grand  idea  which  underlies  the  whole,  and  of  which 
man  is  only  the  nobler  part. 

The   atmosphere  is   a  vast   ocean    of   aeriform 

matter,  enveloping  the  earth  like  a  mantle,  and 

rising  to  the  height  of  many  miles  above 

De8criptlonof  /.      .     .       . 

the  atmos-  our  heads,  but  constantly  diminishing  in 
density  as  the  elevation  increases.  At 
the  height  of  about  three  miles  and  a  half  (3.43) 
the  density  is  only  one  half  as  great  as  at  the 
level  of  the  sea ;  and  at  the  height  of  forty  miles 
it  is  less  than  in  the  exhausted  receiver  of  the 
best  air-pumps.  How  much  higher  than  this  the 
atmosphere  extends,  it  is  impossible  to  determine 
with  accuracy.  In  this  ocean  of  air  all  bodies  on 
the  surface  of  the  globe  are  immersed.  It  is  so 
subtile  that  it  penetrates  into  the  minute  pores 
of  matter,  and  fills  the  cavities  of  all  organized 
being.  It  is  the  medium  in  which  all  vital  pro- 
cesses both  of  plants  and  animals  take  place,  and 
in  which  all  human  activity  has  its  seat.  Let  us 
see  now  with  what  wisdom  its  properties  have 
been  adapted  to  the  important  ends  which  it  is 
appointed  to  subserve. 

Consider,  in  the  first  place,  the  physical  state  of 

the  atmosphere,  its  very  aeriform  condition.     This 

air  is  as  truly  matter  as  the  solid  planks 

Physical  state  J 

of  the  atmos-     on  which  we  are  treading,  or  the  granite 

rocks  on  which  this  building  rests.     It  is 

far  less  dense,  it  is  true,  but  then  it  has  all  the 

essential  properties  of  matter.     It  fills  space.     It 


LECT.I.]  TESTIMONY   OF   THE  ATMOSPHERE.  17 

resists  with  an  ever-increasing  force  all  attempts 
to  condense  it ;  and,  moreover,  it  has  weight.  But 
how  different  in  condition  from  the  solid  rock  !  — 
so  different  that  to  the  uneducated  it  hardly  seems 
material ;  and  in  our  common  language  we  speak 
of  a  space  which  is  filled  only  with  air  as  empty. 
Its  particles  are  endowed  with  such  perfect  free- 
dom of  motion,  and  yield  so  readily  to  the  slightest 
pressure,  that  we  move  through  it  without  feeling 
its  presence.  It  is  firm  enough  to  support  the 
wings  of  the  lark  as  he  mounts  the  sky,  and  yet 
so  yielding  as  not  to  detain  the  tiniest  insect  in 
its  rapid  flight. 

The  physical  condition  of  the  atmosphere  will 
still  further  excite  our  admiration,  when  we  con- 
sider  the   wonderful   play  of   forces    by  TWO  opposing 
which   it    is    upheld.      It   may    not    be  forcesacti^ 


in  the  atmos- 


known  to  you  all  that  upon  this  mass  phere> 
of  air,  outwardly  so  calm  and  passive,  there  are 
constantly  acting  two  mighty  forces,  —  the  force 
of  gravitation  and  the  force  of  heat.  In  virtue 
of  the  force  of  heat  the  particles  of  the  atmos- 
phere mutually  repel  each  other,  and  the  whole 
mass,  like  a  great  bent  spring,  tends  to  break 
from  its  confinement  and  to  expand  into  the  sur- 
rounding space ;  but  this  it  cannot  do,  for  by  the 
power  of  gravitation  it  is  held  with  a  firm  grasp 
to  the  surface  of  the  globe.  Were  this  grasp  for 
a  moment  relaxed,  the  atmosphere  would  dash 
off  with  explosive  violence  and  be  lost  in  the 
immensity  which  surrounds  us.  How  great  the 


18  BELIGION   AND    CHEMISTRY.  [LECT.  I. 

force  is  which  is  required  to  restrain  the  expan- 
sive tendency  of  the  atmosphere  few  persons 
have  an  adequate  conception,  because  the  two 
opposing  forces  are  so  perfectly  balanced  that  we 
are  obliged  to  call  in  the  aid  of  experiment  in 
order  to  render  their  effects  evident.  So  true  is 
this,  that  the  world  never  even  dreamed  of  their 
existence  until  within  two  hundred  years,  and  the 
story  of  the  discovery  is  one  of  the  most  remark- 
able in  the  history  of  inductive  philosophy.  This 
story  is  well  known ;  but  as  it  is  short,  and 
teaches  us  an  important  truth,  you  will  pardon 
its  repetition. 

Every  one  who  has  seen  a  common  pump  is 
familiar  with  the  fact  that  it  is  the  pressure  of 
"Nature  abhors  the  air  which  causes  the  water  to  rise 
in  the  suction-pipe,  and  this  suction  is 
one  manifestation  of  that  force  by  which  the 
atmosphere  is  held  so  firmly  to  the  surface  of 
the  globe.  The  pump,  however,  was  used  long 
before  the  discovery  of  the  pressure  of  the  at- 
mosphere, and  its  action  was  explained  by  a  prin- 
ciple which  seemed  perfectly  satisfactory  then, 
but  which  sounds  strange  enough  to  modern  ears. 
The  principle  appears  first  to  have  originated  with 
the  Aristotelians,  and  was  expressed  in  the  phrase, 
"Nature  abhors  a  vacuum."  These  ancient  phi- 
losophers noticed  that  space  was  always  filled  with 
some  material  substance,  and  that  the  moment  a 
solid  body  was  removed  air  or  water  always 
rushed  in  to  fill  the  empty  space.  Hence  they 


LEOT.I.]  TESTIMONY    OF   THE   ATMOSPHERE.  19 

concluded  that  it  was  a  universal  law  of  nature 
that  space  could  not  exist  unoccupied  by  matter, 
and  the  phrase  just  quoted  was  merely  their 
figurative  expression  of  this  philosophical  idea. 
When,  for  example,  the  piston  of  a  common  pump 
was  drawn  up,  the  rise  of  the  water  was  explained 
by  declaring,  that,  as  from  the  nature  of  things 
a  vacuum  could  not  exist,  the  water  necessarily 
filled  the  space  deserted  by  the  piston. 

This  physical  dogma  served  the  purpose  of  natu- 
ral philosophy  for  two  thousand  years,  and  it  was 
not  until  the  seventeenth  century  that  „ 

*  Florentine 

men  discovered  any  limit  to  nature's  ab-  pump-makers 
horrence  of  a  vacuum.  Near  the  middle 
of  the  century  some  engineers  were  employed  by 
the  Duke  of  Tuscany  to  sink  a  well  in  the  neigh- 
borhood of  Florence  to  an  unusual  depth.  They 
finished  their  work,  but  on  adjusting  the  pump 
they  found  to  their  surprise  that  it  would  not  work. 
With  all  their  efforts  the  water  would  rise  only  a 
little  more  than  thirty  feet,  and  by  no  ingenuity  or 
skill  could  they  raise  it  an  inch  higher.  More  dis- 
gusted with  nature  than  nature  was  with  the  vacu- 
um in  their  pump,  they  applied  to  Galileo,  then  an 
old  man,  living  in  his  villa  on  the  brow  of  Fiesole. 
He  could  not  aid  them,  but  he  is  said  to  have 
replied,  half  in  jest,  half  in  earnest,  that  nature  did 
not  abhor  a  vacuum  above  ten  metres.  Had  this 
incident  occurred  earlier  in  his  career,  Galileo  would 
undoubtedly  have  added  to  the  other  jewels  of  his 
crown  a  brighter  gem  than  all,  but  now  the  vigor 


20  RELIGION   AND    CHEMISTRY.  [Lucr.  I. 

of  his  manhood  was  spent ;  he  had  done  his  work, 
and,  worn  out  by  the  persecution  of  a  bigoted 
priesthood,  he  was  peacefully  resting  from  his  life's 
labor,  and  calmly  awaiting  the  close. 

But  the  key  which  the  incident  had  furnished 
was  not  lost.  It  passed  into  able  hands,  and  it  was 
the  fortune  of  Torricelli,  Galileo's  best  pupil,  to 
unlock  the  secret.  This  young  Italian  philosopher, 
whose  clear  intellect  had  been  trained  in  the  me- 
chanical philosophy  of  his  great  master,  saw  at 
once  that  a  column  of  water  thirty-three  feet  high, 
and  no  higher,  could  not  be  sustained  in  a  cylindri- 
cal tube  by  a  mere  metaphysical  abstraction. 

This  effect,  he  said,  must  be  the  result  of  some 
mechanical  force  equivalent  to  the  weight  of  the 
mass  of  water  sustained.  It  was  not  difficult  to 
prove  the  correctness  of  this  reasoning,  for  it  was 
evident  that  if  a  column  of  water  was  sustained  at 
the  height  of  thirty-three  feet  in  the  suction-pipe 
of  a  pump  by  a  constant  force,  the  same  force  could 
only  sustain  a  column  of  a  heavier  liquid  at  a  pro- 
portionally less  height.  So  Torricelli  tried  mer- 
cury, a  liquid  thirteen  and  a  half  times  heavier 
than  water,  and  the  result  was  as  he  had  antici- 
pated. The  force  which  raised  the  column  of 
water  thirty-three  feet  could  only  raise  a  column 
of  mercury  to  the  height  of  thirty  inches,  which  is 
thirteen  and  a  half  times  less  than  thirty-three  feet. 
Torricelli  did  not,  however,  make  this  experiment 
with  a  pump,  but  with  an  apparatus  of  his  own, 
much  simpler  and  equally  effective. 


LECT.L]  TESTIMONY   OF   THE   ATMOSPHERE.  21 

He  took  a  long  glass  tube,  open  at  one  end, 
filled  it  with  mercury,  and,  having  closed  the  open- 
ing with  his  thumb,  inverted  the  tube,  Experiment  of 
and  plunged  the  open  end  in  a  basin  of  Torricelu- 
mercury;  on  removing  his  thumb  the  mercury, 
instead  of  remaining  in  the  tube,  and  thus  satisfy- 
ing nature's  abhorrence  of  a  vacuum,  fell,  as  he 
expected,  and,  after  a  few  oscillations,  came  to  rest 
at  a  height  of  about  thirty  inches  above  the  level 
of  the  mercury  in  the  basin.  The  correctness  of 
his  induction  having  been  thus  verified,  Torricelli 
at  once  concluded  that  it  must  be  the  pressure  of 
the  air  which  sustained  both  the  water  in  the 
pump  and  the  mercury  in  his  tube. 

This  experiment  excited  a  great  sensation  in  Eu- 
rope ;  but,  as  might  naturally  have  been  expected, 
the  old  physical  dogma  was  not  easily  Demonstration 
laid  aside,  and  Torricelli  did  not  live  to  ofpascal- 
see  his  opinion  generally  received.  It  was  left  to 
the  celebrated  Blaise  Pascal  to  convince  the  world 
that  Torricelli  was  right, 'and  this  he  did  by  one 
of  those  master  strokes  of  genius  which  at  once 
silence  controversy. 

"If,"  said 'Pascal,  "it  be  really  the  weight  of  the 
atmosphere  under  which  we  live  that  supports  the 
column  of  mercury  in  Torricelli's  tube,  we  shall 
find,  by  transporting  this  tube  upwards  in  the 
atmosphere,  that  in  proportion  as  it  leaves  below 
it  more  and  more  of  the  air,  and  has  consequently 
less  and  less  above  it,  there  will  be  a  less  column 
sustained  in  the  tube,  inasmuch  as  the  weight  of 


22  RELIGION   AND    CHEMISTRY.  [LECT.  I. 

the  air  above  the  tube,  which  is  declared  by  Torri- 
celli  to  be  the  force  which  sustains  it,  will  be  dimin- 
ished by  the  increased  elevation  of  the  tube." 

Accordingly  Pascal  carried  the  tube  to  the  top 
of  a  church-steeple  in  Paris,  and  observed  that  the 
mercury  fell  slightly,  but  not  satisfied  with  this 
result,  he  wrote  to  his  brother-in-law,  who  lived 
near  the  high  mountain  of  Puy  de  Dome,  in 
Auvergne,  to  make  the  experiment  there,  where 
the  result  would  be  more  decisive. 

"You  see,"  he  writes,  "that  if  it  happens  that 
the  height  of  the  mercury  at  the  top  of  the  hill 
be  less  than  at  the  bottom,  (which  I  have  many 
reasons  to  believe,  though  all  those  who  have 
thought  about  it  are  of  a  different  opinion,)  it  will 
follow  that  the  weight  and  pressure  of  the  air  are 
the  sole  cause  of  this  suspension,  and  not  the 
horror  of  a  vacuum ;  since  it  is  very  certain  that 
there  is  more  air  to  weigh  on  it  at  the  bottom  than 
at  the  top ;  while  we  cannot  say  that  nature  ab- 
hors a  vacuum  at  the  foot  of  a  mountain  more  than 
on  its  summit."  M.  Perrier,  Pascal's  correspondent, 
made  the  observation  as  he  desired,  and  found  a 
difference  of  about  three  inches,  "  whifch,"  as  he  re- 
plies, "ravished  us  with  admiration  and  astonish- 
ment." 

Thus  it  was  that  man  first  learned  to  recognize 
the  existence  of  that  power,  which  retains  the  at- 
mosphere on  the  surface  of  the  globe,  and  the  his- 
tory of  the  discovery  should  humble  our  intellect- 
ual pride  and  teach  us  to  hold  our  knowledge  with 


LECT.L]  TESTIMONY   OF   THE   ATMOSPHERE.  23 

reverence  and  humility.  This  old  scientific  dogma 
of  the  seventeenth  century  never  fails  The  old  dogma 
to  excite  a  smile,  and  we  are  inclined  a  partial  trutht 
to  wonder  how  man  could  ever  have  believed 
what  now  appears  so  absurd ;  but  if,  like  an  anti- 
quary, we  imbue  our  minds  with  the  spirit  of  that 
age,  it  will  be  seen,  not  only  that  the  dogma  was 
not  essentially  absurd,  but  also  that  the  philo- 
sophical idea,  clothed  in  those  quaint  terms,  ap- 
peared to  the  scientific  men  of  the  period  as  truly 
a  legitimate  induction  from  observed  facts,  as  the 
law  of  gravitation  seems  to  us.  And  the  induc- 
tion was  legitimate;  but  since  the  known  facts  did 
not  cover  the  whole  ground,  they  gave  only  a 
very  partial  truth.  The  Grand  Duke's  pump  was 
the  first  failing  case,  and  proved,  not  that  the  old 
principle  was  absolutely  false,  but  only  that  its 
application  was  very  limited. 

Thanks  to  Galileo,  Torricelli,  Pascal,  and  Newton, 
—  noble  line  of  genius,  —  nature's  abhorrence  of 
a  vacuum  gave  place  to  the  law  of  gravitation, 
and  two  centuries  of  unparalleled  scientific  activity 
have  only  served  to  confirm  the  truth,  and  extend 
the  domain  of  Newton's  grand  generalization ;  but 
even  after  this  signal  triumph,  who  now  feels  fully 
assured  that  the  law  of  gravitation  may  not  find 
its  failing  case  ?  and  when,  two  centuries  hence,  the 
future  historian  comes  to  write  the  history  of  in- 
ductive philosophy,  who  can  feel  certain  that  -  Aris- 
totle's dogma  and  Newton's  law  may  not  both  be 
condescendingly  noticed  among  the  partial  truths 


24  BELIGION  AND    CHEMISTRY.  [LECT.  I. 

which  served  the  purposes  of  science  in  its  infancy 
and  childhood? 

Let  me  not  be  understood  to  imply  a  belief  that 

man  cannot  attain  to  any  absolute  scientific  truth, 

for  I  believe  that  he  can,  and  I  feel  that 

Distinction  _ .  ,      .  .   . 

between  fact  every  great  generalization  brings  him  a 
and  theory.  ^^  nearer  fa  tke  promised  goal  ;  but  I 

wish  here  at  the  outset  most  strongly  to  impress 
the  distinction  between  the  undoubted  facts  of  sci- 
ence, and  the  laws  and  principles  which  have  grown 
up  around  them,  and  by  which  they  have  been  em- 
bodied in  our  systems  of  philosophy,  —  the  distinc- 
tion, in  a  word,  between  the  observed  phenomena 
of  nature,  and  man's  interpretation  of  the  phe- 
nomena. 

This  distinction,  so  obvious  when  stated,  is  too 
often  forgotten,  and  is  necessarily  overlooked  in  our 
scientific  text-books.  It  is  the  sole  aim  of  these 
elementary  treatises  to  teach  the  present  state  of 
knowledge,  and  they  would  fail  in  their  object  if 
they  attempted  by  a  critical  analysis  to  separate  the 
phenomena  from  the  laws  or  systems  by  which  alone 
the  facts  of  nature  are  correlated  and  rendered 
intelligible.  But  although  while  studying  science 
itself,  we  may  for  the  time  waive  the  distinction 
between  fact  and  theory,  the  moment  we  come  to 
compare  the  results  of  science  with  the  eternal 
truths  of  religion,  the  distinction  here  enforced  be- 
comes of  paramount  importance,  and  it  must  be 
our  chief  aim  to  separate  that  which  is  absolute 
and  eternal  truth  from  that  which,  even  in  its  high- 


LBCT.L]  TESTIMONY   OF   THE   ATMOSPHERE,  25 

est  development,  is  the  result  of  human  thought, 
and,  like  all  things  human,  subject  to  limitations  and 
liable  to  change. 

Had  this  distinction  been  always  borne  in  mind, 
the  controversies  between  the  philosophers  and  the 
churchmen  would  have  been  less  bitter  and  more 
fruitful  in  truth ;  the  philosophers  would  have  been 
willing  to  waive  their  theories,  and  the  churchmen 
would  have  been  led  to  respect  the  results  of 
science,  and  conform  their  theology  to  the  indis- 
putable truths  which  God  has  been  pleased  to  re- 
veal through  nature  no  less  plainly  than  in  his 
written  word ;  and  if  the  trite  anecdote  of  Galileo 
and  the  pump-makers  will  serve  to  impress  the  dis- 
tinction on  our  minds,  this  digression  will  not  have 
been  made  in  vain. 

You  must  all  have  recognized  in  Torricelli's 
tube  our  modern  barometer.  By  means  of  this 
well-known  instrument  we  can  readily  pressure  of  the 
estimate  the  pressure  of  the  atmosphere,  atmosPhere- 
and  determine  the  amount  in  our  human  stand- 
ards of  measurement.  It  can  be  readily  proved 
that  the  pressure  of  the  atmosphere  is  about  fif- 
teen pounds  on  every  square  inch  of  the  earth's 
surface,  and  if,  starting  from  this  well-known  fact, 
you  calculate  the  amount  of  pressure  on  any  ex- 
tended surface,  you  will  be  astonished  at  the  result. 
For  example,  the  pressure  exerted  by  the  atmos- 
phere on  the  area  on  which  this  building  stands 
is  vastly  greater  than  the  whole  weight  of  the 
building  itself.  The  pressure  on  a  man  of  ordi- 


26  KELIGION   AND    CHEMISTRY.  [LECT.  I. 

nary  stature  is  about  sixteen  tons;  that  on  one 
square  mile  of  surface  is  equal  to  over  twenty-six 
million  tons. 

How  great,  then,  must  be  the  pressure  on  the 
whole  surface  of  the  globe,  or,  what  is  the  same 
thing,  how  great  is  the  intensity  of  that  ever-act- 
ing power,  which  holds  the  atmosphere  in  its  ap- 
pointed place !  It  would  not  be  difficult  to  calcu- 
late the  amount  and  to  express  it  in  numbers ;  but 
these  numbers  would  convey  to  you  no  definite 
idea,  for  our  minds  are  incapable  of  forming  an 
adequate  conception  of  such  immensity.  The  at- 
tempt to  grasp  it  only  exposes  our  weakness,  and 
yet  this  force,  immense  as  it  is,  is  so  delicately 
balanced  by  the  sweet  influences  of  the  sunbeam, 
that  it  does  not  so  much  as  shake  the  aspen-leaf  or 
break  the  gossamer.  If  we  believe  no  more  than 
this,  that  the  world  was  once  created  by  God,  what 
must  be  the  power  and  wisdom  of  a  being  who 
could  appoint  these  mighty  forces  and  adjust  them 
with  such  perfect  precision !  But  if  we  also  be- 
lieve that  these  forces  are  direct  emanations  of 
Divine  Power,  —  that  it  is  God  himself  who  with 
His  own  right  hand  holds  the  atmosphere  in  its 
place,  and  appoints  its  bounds,  —  then  all  nature 
assumes  a  more  glorious  aspect,  and  we  feel  that 
we  are  indeed  surrounded  by  the  Divine  Presence. 
Yet  this  force,  which  we  find  so  far  beyond  our 
powers  of  conception,  is  but  a  secondary  phase  of 
that  immeasurably  greater  power  which  "brings 
forth  Mazzaroth  in  his  season,  and  guides  Arcturus 


LECT.I.]  TESTIMONY   OF   THE  ATMOSPHERE.  27 

with  his  sons."  How  futile  all  attempts  to  measure 
Divine  power !  We  select  some  one  of  the  feeble 
forces  acting  around  us,  and  succeed  in  reducing 
its  value  to  our  human  standards  of  comparison, 
and  expressing  this  value  in  numbers;  but  the 
numbers,  when  obtained,  are  beyond  our  grasp, 
and  we  find  that  we  have  merely  mounted  to  a 
little  higher  platform,  from  which  we  discover 
numberless  other  forces  immeasurably  greater 
than  the  first.  Something,  however,  has  been 
gained.  We  have  attained  to  the  idea  of  the  in- 
finite ;  and  to  thoroughly  apprehend  the  existence 
of  the  infinite,  is  to  take  the  first  step  towards 
recognizing  the  existence  of  a  God. 

I  know  it  will  be  said  that  man  cannot  compre- 
hend the  infinite,  and  if  by  this  statement  it  is 
only  meant  to  affirm  the  declaration  of  ^  idea  of  the 
the  Bible,  that  man  cannot  "find  out  the  inflnite* 
Almighty  unto  perfection,"  not  even  the  most  vis- 
ionary dreamer  would  question  the  position.  But 
there  is  a  class  of  philosophers  at  the  present  day 
who  think  to  enforce  the  authority  of  revelation 
by  maintaining  the  doctrine  that  man  can  know 
absolutely  nothing  of  the  infinite,  —  nothing  more 
than  he  now  knows  of  the  facts  or  principles  of 
science  to  be  hereafter  discovered;  that,  indeed, 
the  very  term  infinite  implies  a  negation  of  all 
cognizable  qualities. 

To  me,  this  position  seems  fatal  to  the  very 
cause  it  is  intended  to  defend,  and  surrenders  all 
the  approaches  of  the  citadel  to  the  infidel.  For 


28  RELIGION  AND    CHEMISTRY.  [LECT.  I. 

if  there  is  in  man  no  possibility  of  apprehending 
the  infinite,  even  to  the  smallest  degree,  I  can  see 
nothing  to  which  revelation  can  appeal.  He  has 
then  no  power  to  distinguish  between  the  Divine 
and  the  human. 

But  it  is  not  so.  Revelation  implies,  and  all  ex- 
perience shows,  that  man  can  recognize  the  pres- 
ence of  the  infinite  by  attributes  as  clear  and 
unmistakable  as  those  which  mark  the  presence 
of  the  finite  matter  around  him.  He  may  not  be 
able  to  comprehend  a  single  attribute  of  the  infi- 
nite in  its  essence,  but  as  the  mathematician,  deal- 
ing with  infinitesimal  quantities,  which  he  cannot 
fully  understand,  arrives  at  truths  of  the  material 
world  with  all  the  certainty  of  demonstration,  so 
the  mental  philosopher  may  attain  to  moral  truths 
in  regard  to  the  Infinite  Being,  although  the  very 
terms  he  employs  may  be  veiled  in  impenetrable 
mystery. 

And  what  is  the  true  human  conception  of  the 
infinite  ?  It  is  not  merely  something  which  we 
feel  to  be  very  great  indeed,  but  it  is  something 
which  we  feel  surpasses  our  utmost  conceptions  of 
the  great,  —  something  which,  let  us  account  it  as 
great  as  we  please,  yet,  wherever  the  inability  of 
our  mental  power  fixes  the  limit  of  our  conception, 
will  still  be  felt  to  be  greater  than  the  greatest. 
We  cannot  gaze  into  the  heavens  without  awe  •  we 
cannot  examine  the  wonders  of  the  dew-drop  with- 
out reverence ;  we  cannot  look  into  our  own  souls 
without  trembling.  It  is  the  same  invisible  Pres- 


LECT.  L]  TESTIMONY   OF   THE   ATMOSPHERE.  29 

ence  everywhere,  and  however  long  false  philoso- 
phy may  conceal  the  vision,  or  material  cares  and 
pleasures  blind  the  senses,  when  man  once  recog- 
nizes its  existence  he  instinctively  worships  and 
adores. 

The  evidence  of  design  which  we  are  now  study- 
ing is  still  further  enforced  when  we  consider  how 
exactly  the  density  of  the  atmosphere  Density  of  the 
has  been  adjusted  to  the  human  organ-  attnosPhere- 
ism.  By  density  is  meant,  I  need  not  state,  the 
quantity  of  matter  which  the  atmosphere  con- 
tains in  a  given  volume;  for  example,  in  a  cubic 
yard.  This  quantity  is  capable  of  exact  measure- 
ment, and  although  to  a  certain  extent  variable,  it 
is  constant  in  the  same  place,  under  the  same  con- 
ditions of  temperature  and  pressure. 

In  this  latitude,  at  the  level  of  the  sea,  one  cubic 
yard  of  the  atmosphere  when  dry,  and  under  the 
normal  conditions  of  temperature  and  pressure, 
contains  about  two  pounds  of  air,  and  this  weight 
is  the  measure  of  its  density.  Now  we  find  that 
the  organization  of  plants  and  animals,  including 
man,  has  been  most  skilfully  adjusted  to  the  den- 
sity of  the  air,  and  many  illustrations  of  this  adap- 
tation will  be  met  with  as  we  proceed.  But 
accepting  the  fact  for  the  present  as  universally 
conceded,  let  us  consider  the  conditions  on  which 
this  exact  adaptation  of  the  air  to  our  physical 
organization  rests. 

The  density  of  the  atmosphere  may  be  said  to 
depend  upon  four  conditions :  first,  on  the  inherent 


30  RELIGION   AND    CHEMISTRY.  [LECT.  I. 

nature  of  the  substance  which  we  call  air  itself; 
secondly,  on  the  intensity  of  gravity ;  thirdly,  on 
the  total  quantity  of  air  on  the  globe ;  and,  lastly, 
on  the  temperature.  The  influence  of  the  first 
condition  is  not  understood,  but  that  of  the  last 
three  we  can  readily  trace.  If  the  intensity  of  the 
force  of  gravity  at  the  surface  of  the  earth  were  to 
change,  other  circumstances  remaining  the  same, 
the  density  of  the  atmosphere  would  change  in  the 
same  proportion.  Thus,  for  example,  if  the  inten- 
sity of  gravity  on  the  earth  were  as  great  as  it  is 
on  the  surface  of  the  sun,  the  density  of  the  atmos- 
phere would  be  twenty-eight  times  as  great  as  at 
present;  or  if  this  intensity  were  reduced  to  that 
which  exists  on  the  surface  of  the  moon,  the  den- 
sity would  be  diminished  to  one  sixth  of  the  exist- 
ing density. 

But,  assuming  that  the  intensity  of  the  force 
of  gravity  on  the  surface  of  the  earth  remained 
constant,  precisely  the  same  effect  would  result 
from  any  variation  in  the  total  quantity  of  the 
atmosphere.  Were  the  whole  amount  of  air  on 
the  earth  increased  or  diminished,  the  density 
of  the  atmosphere  at  its  surface  would  also  be 
increased  or  diminished  in  the  same  proportion. 
Still  further,  assuming  that,  while  the  intensity 
of  gravity  and  the  mass  of  the  atmosphere  re- 
mained fixed,  the  temperature  were  changed,  then 
also  the  density  of  the  atmosphere  would  vary, 
and  by  a  quantity  which  can  be  easily  determined. 
By  accurate  experiments  it  has  been  ascertained 


LKOT.I.]  TESTIMONY   OF   THE  ATMOSPHERE.  31 

that  an  elevation  of  temperature  equivalent  to 
about  five  hundred  degrees  of  our  Fahrenheit 
thermometer  would  reduce  the  density  to  one 
half,  and,  on  the  other  hand,  that  a  reduction  of 
temperature  would  increase  the  density  in  the 
same  proportion. 

Consider  next  what  these  relations  imply.  Be- 
flect  that  the  intensity  of  the  force  of  gravity 
depends  upon  the'  mass  of  the  earth.  , 

Evidence  of 

Kemember  that  the  mean  temperature  unity  m  the 
depends  upon  the  distance  of  the  earth 
from  the  sun,  and  you  will  see  that  not  only  the 
actual  size  of  the  earth,  but  also  its  distance  from 
the  sun,  and  the  quantity  of  air  on  its  surface, 
were  all  necessary  conditions,  in  order  that  the 
atmosphere  should  have  its  present  density,  and 
thus  become  the  fit  abode  for  man.  If  any  one 
of  these  conditions  had  been  neglected,  the  result 
would  not  have  been  attained,  and  man,  as  he  ex- 
ists, could  not  have  lived  on  this  globe. 

It  must  then  have  been  He  "who  hath  meted 
"out  heaven  with  the  span,  and  comprehended 
"  the  dust  of  the  earth  in  a  measure,  and  weighed 
"the  mountains  in  scales,  and  the  hills  in  a  bal- 
"  ance,"  who  "  formed  man  of  the  dust  of  the 
"  ground,  and  breathed  into  his  nostrils  the  breath 
"of  life." 

The  unity  of  the  design  implies  the  oneness  of 
the  designer,  and,  although  the  adaptations  just 
considered  may  not  exclude  every  possible  athe- 
istic theory  of  cosmogony,  yet  they  show  conclu- 


32  RELIGION   AND    CHEMISTRY.  [Lacr.  I. 

sively  that,  if  there  is  design  anywhere,  there 
is  design  everywhere  ;  if  there  is  design  in  the 
least,  there  is  design  also  in  the  greatest,  and  design 
in  the  atom  may  thus  confirm  the  evidence  of  design  in 
man. 


LECTUEE    II. 

TESTIMONY   OF   THE   ATMOSPHERE. Concluded. 

DURING  a  recent  journey  in  Switzerland,  at  the 
close  of  a  delightful  summer's  day,  in  the  early 
part  of  July.  I  arrived  at  Interlachen,  in  T 

*  '  Relation  of  the 

company  with  a  number  of  fellow-trav-  atmosphere  to 
ellers.  We  had  been  sailing  on  the  beau- 
tiful lake  of  Brienz,  and  some  minutes  before  we 
reached  our  destination  the  sun  had  set,  and  the 
mountains  had  already  cast  their  long  shadows 
across  the  lake.  Early  in  the  afternoon  the  clouds 
had  settled  on  the  nearer  hills,  and  we  had  been 
disappointed  at  not  obtaining  a  view  of  the  dis- 
tant summits  of  the  Bernese  Oberland;  but  sud- 
denly, as  the  boat  neared  the  shore,  the  magnifi- 
cent peak  of  the  Jungfrau  appeared  from  behind 
the  veil  of  clouds,  clothed  in  her  white  mantle  of 
everlasting  snow,  and  bathed  with  a  flood  of  rosy 
light.  The  effect  thus  heightened  by  the  contrast 
was  grand  beyond  description,  and  as  beautiful  as 
it  was  grand.  It  seemed  like  a  vision  of  the  Heav- 
enly Kingdom,  —  as-  if  the  glory  of  God  had  rested 
on  the  mountain.  The  scene  completely  filled  the 
soul,  and  the  heart  overflowed  with  gratitude  for 
the  blessing  it  enjoyed.  It  was  felt  to  be  one  of 


34  RELIGION  AND    CHEMISTRY.  [LECT.  II. 

the  great  privileges  of  a  lifetime,  and  his  would 
have  been  a  dull  understanding,  and  a  duller  heart, 
which  did  not  recognize  the  Giver  in  the  gift.  The 
view  so  riveted  the  attention  that  we  hardly  no- 
ticed our  arrival,  and  as  we  walked  to  the  hotel  we 
watched  the  successive  shades  of  crimson  and  pur- 
ple as  they  flitted  up  the  mountain,  until  the  last 
blended  in  the  gray  of  the  twilight. 

It  may  not  be  permitted  to  many  to  behold 
the  Jungfrau  blushing  before  her  retiring  lord,  but 
all  have  witnessed  the  same  effect  on  even  a 
grander  scale,  when  the  white  clouds,  piled  up  on 
the  western  horizon  like  vast  mountain  chains, 
become,  at  evening,  resplendent  with  the  rays  of 
the  setting  sun;  and  many  have  watched  their 
varying  tints  of  gold  and  purple,  until  at  last 
their  ghostly  forms  vanished  in  the  dusk  of  the 
evening,  and  the  stars  came  out  to  take  up  with 
their  measured  twinkling  the  silent  song  of  praise. 
Perhaps,  also,  there  may  be  some  who,  after  anx- 
iously watching  through  the  night,  have  felt  their 
hearts  strengthened  and  their  hopes  revived  when 
the  blush  of  morning  reassured  them  of  their  Fa- 
ther's providence,  and  all  nature  smiled  in  the 
floods  of  returning  light. 

All  these  glorious  visions,  all  this  beauty,  and 
all  the  pure  emotions  of  our  hearts  which  they 
excite,  we  owe,  my  friends,  to  the  skill  with  which 
the  physical  qualities  of  the  atmosphere  have  been 
adjusted  to  the  wants  of  our  physical  and  moral 
natures,  and  they  all  thus  become  the  silent  wit- 


LECT.II.]  TESTIMONY   OP   THE   ATMOSPHERE.  35 

nesses  not  only  of  the  wisdom,  but   also  of  the 
goodness  of  our  God. 

We  have  already,  in  the  first  lecture,  discussed 
some  of  the  adaptations  of  the  physical  condition 
of  the  atmosphere  to  the  purposes  which  it  sub- 
serves on  the  globe,  and  I  wish  this  evening  to  de- 
velop still  further  the  same  subject,  by  considering 
a  few  additional  examples ;  and  first  I  will  ask  your 
attention  to  those  evidences  of  design  which  are  to 
be  found  in  the  relations  of  the  atmosphere  to 
light  and  heat.  Here,  however,  I  am  met  by  a  dif- 
ficulty. In  order  to  explain  fully  these  relations  it 
would  be  necessary  to  develop  from  first  princi- 
ples the  sciences  of  optics  and  thermotics,  and  to 
do  this  in  a  popular  manner  would  require  several 
lectures.  These  sciences  furnish  some  of  the  most 
wonderful  evidences  of  design  which  are  to  be 
found  in  nature,  and  I  have  no  doubt  will  be  given 
their  appropriate  place  in  this  series  of  lectures. 
Without,  therefore,  attempting  any  detailed  expla- 
nations, I  will  merely  bring  before  you  a  few  facts, 
drawn  from  these  departments  of  knowledge,  which 
illustrate  the  adaptations  of  the  density  of  the  at- 
mosphere to  its  appointed  ends. 

The  atmosphere,  although  very  much  more  per- 
vious to  light  than  any  kind  of  solid  or  liquid  mat- 
ter, is  far  from  being  perfectly  transparent. 
Indeed,  the  reverse  is  sufficiently  evident  oftheatmos- 
from  our   daily   experience.  '  Every  one  p 
has  noticed  that  distant  objects  appear  less  distinct 
in  proportion   as  they  are   removed,  their  colors 


36  RELIGION   AND    CHEMISTRY.  [LECT.  H. 

become  fainter,  the  contrast  between  light  and 
shade  less  marked,  and  that  they  seem  as  if  cov- 
ered with  a  pale  blue  veil.  This  effect,  always  no- 
ticed on  distant  mountains,  is  owing  to  a  partial 
absorption  of  the  light  while  passing  through  the 
atmosphere ;  for,  were  the  passage  of  the  rays 
wholly  unimpeded,  all  objects,  although  reduced  in 
size  in  proportion  to  their  distance,  would  appear 
equally  distinct,  and  their  colors  equally  brilliant. 
The  transparency  of  the  atmosphere  differs  very 
greatly  under  different  circumstances,  but  it  has 
been  estimated,  that  under  the  most  favorable  con- 
ditions, at  least  thirty  per  cent  of  all  the  light 
coming  from  the  heavenly  bodies  is  absorbed  be- 
fore reaching  the  surface  of  the  earth,  and  in  our 
latitude  at  this  season,  even  when  the  sun  is  on  the 
meridian  and  the  sky  clear,  fully  one  half  of  his 
rays  are  thus  spent.  Do  not  suppose,  however, 
that  all  the  light  so  expended  is  lost.  Quite  the 
contrary,  for  every  particle  of  the  atmosphere,  illu- 
minated by  the  sunbeam,  becomes  itself  a  new 
centre  of  emission,  radiating  the  light  in  every 
direction. 

This  diffusion  of  the  sun's  rays  is  the  cause  of 
that  wonderful  effect  which  we  term  daylight.  I 
say  wonderful  effect,  for  although  so  fa- 
miiiar,  it  is  one  of  the  most  remarkable 
results  of  skilful  adaptation  and  infinite  wisdom. 
The  very  daylight  which  streams  in  at  the  open 
windows  of  our  houses,  filling  them  with  cheerful- 
ness, and  penetrating  to  their  inmost  recesses, 


LECT.H.]  TESTIMONY   OF  THE  ATMOSPHERE.  37 

which  enlivens  the  whole  landscape,  and  which 
bars  and  bolts  cannot  wholly  exclude  even  from 
the  prisoner's  dungeon,  is  another  evidence  of  the 
adjustment  of  the  density  of  the  atmosphere  to  the 
constitution  of  man. 

In  order  that  you  may  see  the  force  of  this  evi- 
dence, let  us  inquire  what  would  be  the  effect  of 
the  sun's  light  if  there  were  no  atmosphere,  assum- 
ing, for  the  sake  of  illustration,  that  man  could  ex- 
ist under  such  conditions.  The  known  principles 
of  optics  will  furnish  an  answer  to  our  question. 
They  inform  us  that  while  all  objects  directly  illu- 
minated by  the  sun  would  shine  so  brilliantly  as  to 
dazzle  the  eye,  everything  else  would  be  in  com- 
plete darkness.  The  interior  of  our  dwellings  would 
be  at  midday  as  dark  as  during  the  darkest  night ; 
and  the  contrast  between  light  and  shadow  would 
be  stronger  than  that  between  the  most  brilliant 
sunlight  and  the  blackest  darkness  now  known. 
Our  eyes,  as  little  fitted  to  such  conditions  as  our 
lungs,  would  be  blinded  by  the  sudden  alternations, 
and  distinct  vision  would  be  rendered  impossible. 

Thus  it  appears  that  the  atmosphere  is  as  much 
an  essential  condition  of  our  seeing  as  of  our  breath- 
ing.    But  more  than  this,  the  immeasur-  Effect  on  the 
able  pleasure  which  we  derive  from  our  lsmdsoaPe- 
sense  of  vision  depends  upon  the  exact  adaptation 
of  the  density  of  the  atmosphere  to  the  organization 
of  the  eye.     Similar  effects  to  those  just  noticed, 
although  of  course  on  a  greatly  diminished  scale, 
would  result,  were  the  density  of  the  atmosphere 


38  RELIGION   AND    CHEMISTRY.  [LECT.  H. 

materially  diminished.  This  is  not  a  matter  of 
theory,  for  such  effects  have  been  frequently  no- 
ticed on  the  summits  of  high  mountains,  where 
the  air  is  much  rarer  than  at  the  sea  level.  On 
the  top  of  Mont  Blanc  the  sky  has  a  blackish 
hue,  and  the  stars  are  seen  at  midday.  The  glare 
of  the  direct  light  is  unsupportable  to  the  eye, 
and  even  the  reflection  from  the  snow  blisters 
the  unprotected  skin,  while  at  the  same  time 
the  contrast  between  light  and  shade,  unnaturally 
increased,  gives  to  all  near  objects  a  peculiar  and 
ghastly  aspect.  This  effect  results,  it  is  true,  from 
a  very  great  diminution  in  the  density  of  the  air; 
but  when  you  reflect  upon  what  delicate  contrasts 
of  light  and  shade  the  beauty  of  a  landscape  de- 
pends,—  the  clearness  of  the  foreground,  the  gray 
of  the  middle  distance,  and  the  tender  purple  of 
the  distant  hills  all  blending  into  one  harmonious 
whole,  —  you  can  appreciate  how  slight  a  change 
would  disturb  the  result,  and  deprive  the  sense 
of  beauty  of  its  purest  enjoyment. 

I  have  thus  far  spoken  only  of  the  influence  of 
the  atmosphere  in  softening  the  intensity  of  the 
rays  of  light,  and  in  diffusing  their  action;  but 
the  atmosphere  has  also,  under  certain  conditions, 
the  power  of  decomposing  the  sun's  rays,  and  thus 
producing,  not  only  those  displays  of  gorgeous 
tints  which  we  witness  in  the  sunset  clouds, 
but  also  the  pure  blue  which  colors  the  dome  of 
heaven. 

In  regard  to  the  precise  means  which  are  em- 


LECT.H.]  TESTIMONY   OF  THE  ATMOSPHEKE.  39 

ployed  by  nature  to  produce  these  results,  scien- 
tific men  are  not  agreed.  It  has  been  Blue  color  of 
proved  that  the  blue  color  of  the  sky  is  the  sky- 
seen  by  reflected  light,  and  it  is  probable  that  the 
color  is  caused  by  repeated  reflections  of  the  sun's 
rays  from  the  surfaces  of  the  innumerable  small 
water-bubbles  which  are  constantly  floating  jn  the 
atmosphere.  You  have  all  noticed  the  blue  color 
of  the  soap-bubble  shortly  before  it  breaks.  This 
color  is  caused  by  the  action  of  the  very  thin  film 
of  water  in  decomposing  the  light  reflected  from 
its  surface,  and  it  is  supposed  to  be  an  action  of 
the  same  sort,  only  very  much  increased  by-  re- 
peated reflections,  which  gives  to  the  sky  its  azure 
hue. 

While  the  blue  color  of  the  sky  appears  to 
result  from  changes  in  the  white  light  of  the  sun 
caused  by  reflection,  it  is  equally  probable 
that  the  sunset  tints  arise  from  changes 
in  the  same  white  light  caused  by  an  unequal 
absorption  of  its  different  colored  rays  during  their 
transmission  through  the  atmosphere.  Here,  again, 
the  vapor  in  the  air  is  supposed  to  be  the  active 
agent ;  and  the  theory  is,  that  the  tints  are  pro- 
duced while  the  vapor  is  condensing  into  clouds,  — 
a  change  which  naturally  occurs  at  sunset.  But 
this  is  a  mere  theory,  and  our  whole  knowledge 
on  these  subjects  is  very  imperfect. 

So  far,  however,  as  our  present  argument  is 
concerned,  it  is  not  essential  that  we  should  un- 
derstand exactly  how  these  glorious  results  are 


40  EELIGION   AND    CHEMISTRY.  [LECT.  II. 

obtained.  It  is  sufficient  that  we  are  constantly 
enjoying  their  beauty,  and  that  we  know  they 
are  owing  to  the  peculiar  constitution  of  the  at- 
mosphere. When  future  discoveries  shall  bring 
to  light  the  methods,  at  present  secret,  by  which 
nature  gilds  the  sunset  clouds  and  covers  our 
beautiful  dwelling-place  with  its  canopy  of  blue, 
we  shall  unquestionably  find  fresh  evidences  of 
God's  wisdom ;  but  even  now,  when  ignorant,  per- 
haps, of  these  hidden  causes,  we  have  that  which 
is  far  more  excellent,  the  most  conclusive  evi- 
dence of  His  goodness  and  love.  Our  Father  has 
not  only  adapted  the  atmosphere  to  the  wants  of 
our  bodies,  and  made  it  conducive  to  our  physical 
enjoyment,  but  he  has  also  made  it  the  scene 
of  the  highest  beauty,  —  a  beauty  which  fills  the 
longings  of  our  souls  and  calls  forth  their  noblest 
and  purest  aspirations.  Man,  sinful  as  he  is,  can- 
not look  up  into  the  pure  blue  of  heaven  without 
a  sense  of  reproach,  and  the  feeling  that  it  is  a 
fit  emblem  of  the  kingdom  of  purity  and  peace. 
And  when  the  setting  sun  lights  up  the  evening 
altar  in  the  west,  who  can  repress  the  rising  prayer 
of  devotion,  and  hesitate  to  believe,  with  the  child, 
that  his  Heavenly  Father  is  smiling  behind  the 
clouds  ?  There  is  a  depth  to  the  beauty  of  nature 
which  man  cannot  fathom.  Poetry  cannot  describe 
it,  and  the  highest  art  only  displays  its  weakness 
when  it  attempts  to  copy  it.  The  savage  feels 
that  it  is  immeasurably  above  him,  and  worships 
it.  The  artist  seeks  to  attain  it,  but  the  more  he 


LEOT.  II.]  TESTIMONY   OF   THE  ATMOSPHERE.  41 

strives,  the  more  it  surpasses  his  power,  and  he 
dies  disappointed,  unless,  happily,  he  finds  that 
the  perfect  ideal  has  been  realized  only  in  Christ, 
and  thus  through  nature  is  led  up  to  nature's 
God.  Yes !  the  beauty  of  nature  is  in  the  Infinite 
Presence  it  conceals,  and,  unconsciously  though  it 
may  be,  it  is  the  spirit,  not  the  matter,  which 
the  artist  loves. 

Such  are  some  of  the  evidences  of  design  which 
we  discover  in  the  relations  of  the  atmosphere  to 
light.  Let  us  now  examine  some  of  its 

Relations  of  the 

relations  to  heat,  which  we  shall  find  not.  atmosphere  to 
less  instructive.  It  was  formerly  sup- 
posed that  the  rays  of  heat,  although  accompany- 
ing the  luminous  rays  in  the  sunbeam,  were  essen- 
tially different  from  those  of  light.  But  it  is  now 
almost  universally  believed  that  the  rays  of  heat 
differ  from  those  of  light  only,  at  most,  as  one  color 
differs  from  another,  and  that -even  the  same  rays, 
which,  falling  on  the  retina  of  the  eye,  excite  the 
sensation  of  light,  when  falling  on  the  nerves  of 
feeling  may  excite  heat.  But  what,  you  may  ask, 
is  the  difference  between  the  different  colors  ?  The 
subject  is  somewhat  abstruse,  but  if  you  will  follow 
me  attentively  for  a  few  minutes  I  will  try  to  make 
it  intelligible. 

Every  one  who  has  dropped  a  stone  into  the 
water  of  a  still  lake  has  noticed  the  system  of 
waves  which,  with  its  ever-increasing  cir- 

'  Wave  motion, 

cles,  spreads  in  every  direction  from  the  illustrated  by 
stone ;  but  all  may  not  know  that  when 


42  RELIGION   AND    CHEMISTRY.  [LECT.  II. 

two  stones  are  struck  together  in  the  air  a  similar 
system  of  aerial  waves  spreads,  in  ever-widening 
spheres,  through  the  atmosphere,  and  that  it  is 
these  waves  breaking  on  the  tympanum  of  our 
ears,  like  the  waves  of  water  on  a  sand-beach,  which 
produce  the  sensation  we  call  sound.  Two  stones 
thus  struck  together  give  rise  to  waves  of  unequal 
size,  following  one  another  at  irregular  intervals; 
and  such  waves  produce  an  unpleasant  sensation 
on  our  auditory  nerves,  which  we  call  noise.  But 
if,  instead  of  striking  together  two  stones,  we  set 
in  vibration  the  string  of  a  piano-forte  or  the  reed 
of  an  organ-pipe,  we  excite  a  system  of  waves,  all 
of  equal  size,  and  succeeding  one  another  with  per- 
fect regularity,  and  these  breaking  on  the  ear  pro- 
duce by  their  regular  beats  what  we  call  a  musical 
note.  If  the  waves  follow  one  another  with  such 
rapidity  that  one  hundred  and  twenty-eight  break 
on  the  tympanum  every  second,  the  note  has  a 
fixed  pitch,  called  in  music  C  natural.  If  the 
waves  come  faster  than  this,  the  pitch  is  higher, 
and  if  less  rapidly  the  pitch  is  lower.  What  you 
are  all  familiar  with  as  the  pitch  of  a  musical  note 
depends,  then,  on  the  rapidity  with  which  the 
waves  of  sound  strike  the  ear,  and  may  evidently 
be  measured  by  the  number  of  waves  breaking  on 
the  tympanum  in  a  second. 

Our  ears  are  so  constituted  that  they  can  hear 
a  musical  note  only  when  within  certain  fixed  lim- 
its of  pitch,  differing  to  a  slight  extent  with  differ- 
ent individuals.  The  deepest  bass  note,  which  can 


LECT.II.]  TESTIMONY    OF   THE  ATMOSPHERE.  43 

be  heard,  as  such,  by  a  good  ear,  is  produced  by 
about  eight  waves  in  a  second.  If  the  waves 
strike  less  rapidly  than  this,  they  are  perceived  as 
distinct  beats,  and  beginning  at  this  note  the  musi- 
cal scale  ascends  to  a  note  caused  by  twenty-four 
thousand  waves  a  second,  which  is  the  highest  note 
perceptible  by  human  sense.  The  range  of  a  piano 
generally  extends  from  a  note  produced  by  sixteen 
waves  in  a  second,  to  one  caused  by  one  thousand 
and  twenty-four  waves  in  a  second,  as  is  shown  by 
the  accompanying  table. 

^StT™  Sn^eT 

in  one  second. 

C  — 3  70  16 

C  — 2  35  32 

C  — 1  17.5  64  ' 

d             8.75  128 

C2            4.375  256 

C3             2.178  512 

C4             1.093  1024 

Name  of  Note  Cj         DI         E^         Fj         GI         A-i         Bj         C2 

Number  of  Waves         128        144       160      170§     192      213£     240        256 

atio  of  each  number  ? 
to  that  of  Note  C,     J 


Ratio  of  each  number  \    -t  9  5  4  3  i  1 5.  9 

1  f  f  f  f          ~B  ^ 


Sounds  of  the  highest  pitch,  like  the  cry  of 
some  insects,  become  disagreeable,  and  by  some 
persons  cannot  even  be  distinguished.  It  is  quite 
possible  to  produce  a  sound,  which,  though  pain- 
fully shrill  to  one  person,  shall  be  entirely  unheard 
by  another.  Professor  Tyndall,  in  his  very  inter- 
esting work  on  the  glaciers  of  the  Alps,  relates  an 


44  RELIGION   AND    CHEMISTRY.  [LECT.  II. 

instructive  anecdote  of  this  sort,  which  I  give  in 
his  own  language. 

"I  once  crossed  a  Swiss  mountain  in  company 
with  a  friend;  a  donkey  was  in  advance  of  us, 
and  the  dull  tramp  of  the  animal  was  plainly 
heard  by  my  companion;  but  to  me  this  sound 
was  almost  masked  by  the  shrill  chirruping  of 
innumerable  insects,  which  thronged  the  adjacent 
grass;  my  friend  heard  nothing  of  this,  it  lay 
quite  beyond  his  range  of  hearing." 

There  may,  therefore,  be  innumerable  sounds  in 
nature  to  which  our  ears  are  perfectly  deaf, 
although  they  are  the  sweetest  melody  to  more 
refined  senses.  Nay,  more,  the  very  air  around 
us  may  be  resounding  with  the  hallelujahs  of  the 
heavenly  host,  when  our  dull  ears  hear  nothing 
but  the  feeble  accents  of  our  broken  prayers. 

We  have  been  studying,  my  friends,  the  nature 

of  sound,  in  order  to  comprehend   more   readily 

the  nature  of  light  and  heat,  for  the  phe- 

Waves  of  light.  •       i      i     i 

nomena  included  under  these  names  are 
produced,  like  the  phenomena  of  sound,  by  waves, 
not,  however,  by  waves  in  the  air,  but  by  waves 
in  a  medium  which  is  as  much  more  subtile  than 
air  as  air  is  more  subtile  than  water,  —  indeed,  a 
medium  so  exceedingly  thin  that  it  eludes  all  our 
powers  of  chemical  analysis;  but  which,  as  we 
assume,  pervades  all  space,  and  this,  too,  whether 
the  space  is  filled  or  not,  at  the  same  time,  by 
other  forms  of  matter.  We  call  this  medium 
ether,  and  through  it  the  waves  of  light  speed 


LECT.II.]  TESTIMONY    OF   THE  ATMOSPHERE.  45 

with  an  inconceivable  rapidity.  Sound  travels 
1,100  feet  in  a  second,  but  a  wave  of  light  spans 
192,000  miles  in  the  same  time,  and  starting  from 
the  sun  on  its  journey  of  unnumbered  years,  to 
Sirius  or  Arcturus,  leaves  the  whole  solar  system 
behind  in  a  single  hour. 

Yet  great  as  is  the  difference  of  velocity,  the 
analogy  between  sound  on  the  one  side  and  light 
or  heat  on  the  other  is  complete.  Every  luminif- 
erous  body,  like  this  candle-flame,  excites  in  the 
tenuous  ether  a  system  of  waves,  which  spread  in 
ever  enlarging  spheres  with  the  immense  velocity 
just  described ;  and  it  is  these  little  billows  which, 
passing  through  the  humors  of  the  eye,  and  break- 
ing on  the  retina,  produce  the  sensation  we  call 
light,  or,  falling  on  the  skin,  excite  the  less  delicate 
nerves  of  feeling,  and  cause  the  sensation  of  heat. 

Moreover,  the  difference  between  colors  is  of 
precisely  the  same  kind  as  the  difference  between 
notes.  Red,  yellow,  green,  blue,  violet, 

0  .  .  Cause  of  color. 

&c.,  are  names  we  give  to  sensations 
caused  by  waves  of  ether  breaking  at  regular  inter- 
vals on  the  retina.  Color  corresponds  to  pitch,  and 
—  what  may  seem  to  you  incredible — we  are  able 
to  calculate  from  actual  measurements  the  number 
of  waves  of  ether  which  must  break  on  the  retina 
in  a  second  in  order  to  produce  the  sensation  of  a 
given  color.  Here  are  some  of  the  numbers,  and, 
extravagant  as  they  appear,  they  are  the  sober 
results  of  science,  and  have  been  as  accurately  de- 
termined as  the  magnitudes  and  distances  of  as- 
tronomy. 


46  KELIGION   AND    CHEMISTRY.  [LECT.  II. 

p  ,  Length  of  waves  *  Number  of  waves 

in  parts  of  an  inch.  in  a  second. 

Rgd     ...      256  ten-millionths      .     .     .     477  million  million. 

Orange  240  "  506  "         " 

Yellow  227  "  535  «        " 

Green  211  «  577  "        " 

Blue  196  «  622  " 

Indigo  185  «  658 

Violet  174  "  699 

It  is  actually  true,  that  when  we  are  receiving 
the  sensation  of  red  there  are  no  less  than  477  mil- 
lion millions  of  ether  waves  breaking  on  the  retina 
of  our  eyes  every  second.  And  more  than  this,  we 
have  measured  the  length  of  these  waves,  and 
we  know  that  the  length  of  a  wave  of  red  light 
from  crest  to  crest  is  ^-^OT  °f  an  mcn-  By  exam- 
ining the  table  you  will  also  discover  that  the  sen- 
sation of  red,  as  compared  with  other  colors,  results 
from  the  smallest  number  of  waves,  and  that  these 
waves  are  comparatively  large.  On  the  other  hand, 
the  sensation  of  violet  is  caused  by  the  largest 
number  of  waves,  which,  however,  are  proportion- 
ally small  in  size.  The  red  light,  therefore,  cor- 
responds to  low,  and  the  violet  to  high  notes  of 

*  A  given  wave-length  corresponds  to  each  point  on  the  line  of  the 
solar  spectrum  to  be  described  further  on.  The  numbers  given  in  the 
table  are  to  be  regarded  merely  as  the  mean  values  for  each  color, 
measured  at  points  on  the  spectrum,  marked  by  certain  prominent  dark 
lines,  called  Frauenhofer's  lines.  The  solar  spectrum,  when  formed  by 
a  beam  of  light  admitted  into  a  dark  chamber  through  a  narrow  slit,  is 
seen  crossed  by  thousands  of  these  lines,  which  have  a  fixed  position, 
and  therefore  serve  to  mark  definite  points  on  this  otherwise  continuous 
band  of  blending  colors. 


LECT.II.]  TESTIMONY   OP   THE  ATMOSPHERE.  47 

music,  and  between  these  extremes  there  exists 
every  gradation  of  pitch,  which  is  here  manifested 
in  color. 

Waves  of  all  the  dimensions  given  in  the  table, 
together  with  waves  of  every  possible  length  be- 
tween certain  extremes, — which  are  far  The  soiar  spec- 
wider  than  those  indicated  above,  —  move  trum> 
together  in  the  sunbeam,  and  their  combined  im- 
pression produces  the  sensation  of  white  light. 
We  have  a  very  simple  way  of  analyzing  the  sun- 
beam and  separating  its  different  color-producing 
waves.  The  method  consists  in  passing  the  sun- 
beam through  a  glass  prism.  The  prism  has  the 
power  of  bending  the  beam  from  its  rectilinear  di- 
rection; but  it  does  not  change  the  direction  of 
the  motion  of  all  the  waves  to  the  same  extent. 
The  longer  waves,  which  give  the  sensation  of 
red,  are  bent  from  their  course  much  less  than 
the  shorter  waves,  which  produce  the  sensation  of 
violet,  while  waves  of  an  intermediate  length 
take  a  course  between  the  two.  Hence,  after 
emerging  from  the  prism  the  directions  of  the 
different  waves  diverge,  and  if  we  receive  the 
beam  of  light  thus  analyzed,  on  a  screen,  the 
various  color-producing  waves  strike  the  screen 
at  different  points  of  a  continuous  line.  A  more 
or  less  narrow  band  on  the  screen  will  thus  be 
illuminated  with  lights  of  different  colors  in  the 
order,  Eed,  Orange,  Yellow,  Green,  Blue,  Indigo, 
Violet,  and  this  beautiful  phenomenon  is  familiar 
to  almost  every  one  under  the  name  of  the  solar 
spectrum. 


48  RELIGION   AND    CHEMISTRY.  [LECT.  H. 

Here,  where  we  have  the  whole  scale  of  colors 
spread  out  before  us,  the  analogy  of  light  to 
Analogy  be-  sound  becomes  still  more  evident.  As 


there  are  persons   who  cannot  hear  the 

and  musical 

notes.  shrill   sound   of   some   insects,   so    there 

are  many  who  cannot  see  certain  colors  of  the 
spectrum,  and  as  there  are  unquestionably  innu- 
merable sounds  in  nature  which  are  inaudible  to 
our  ears,  so  there  are  innumerable  waves  in  the 
ether  which  are  powerless  to  produce  the  sensa- 
tion of  light.  Moreover,  singular  as  it  may  seem, 
we  have  more  palpable  evidence  of  the  existence 
of  these  non-luminiferous  waves  than  we  can  ob- 
tain in  the  case  of  sound.  There  are  waves  in 
the  ether  far  smaller,  and  undulating  far  more 
rapidly,  than  those  which  produce  violet  light; 
so  small  that  they  do  not  even  jar  the  nerves  of 
the  retina,  but  which,  nevertheless,  breaking  on 
the  prepared  plate  of  the  photographer,  leave 
there  an  impression  which,  developed  by  his  skill, 
becomes  a  beautiful  copy  of  nature  or  of  art.  On 
the  other  hand,  there  are  waves  in  this  same  ether 
so  large  that  the  delicate  retina  cannot  vibrate  in 
unison  with  their  rough  beats,  but  which,  never- 
theless, breaking  on  the  surface  of  the  skin,  dis- 
turb the  coarser  nerves  of  feeling,  and  produce  the 
glow  of  heat.  Most  of  the  waves  which  impress 
the  optic  nerve  will  also  affect  the  nerves  of  feel- 
ing ;  but  the  reverse  is  not  true,  for  many  of  the 
waves  which  produce  the  sensation  of  heat  are 
far  too  large,  and  undulate  too  slowly,  to  set  in 
vibration  the  retina  of  the  eye. 


LECT.  II.]  TESTD10NY   OF   THE  ATMOSPHERE.  49 

I  hope  that  I  have  been  able  to  make  clear  two 
points,  —  first,  that  light  and  heat  are  forms  of 
motion ;  second,  that  the  differences  in  the  phe- 
nomena which  have  been  referred  to  these  two 
agents  are  simply  different  sensations  or  different 
effects*  produced  by  the  same  wave-motion.  It 
would  be  highly  interesting  in  this  connection 
to  examine  the  wonderfully  delicate  adjustments 
and  to  follow  out  the  peculiarly  intricate  motions 
which  concur  to  produce  the  phenomena  of  light 
and  heat ;  for  they  are  in  themselves  most  strik- 
ing illustrations  of  the  wisdom  of  the  Creator. 
But  this  would  lead  us  too  far  from  our  proposed 
plan,  and  I  must  content  myself  with  the  few 
facts  already  given,  which  were  necessary  to  illus- 
trate the  relations  of  the  atmosphere  to  the  ther- 
mal conditions  of  our  globe. 

From  the  principles  stated,  it  is  evident  that 
the  atmosphere  must  act  in  diffusing  heat  just 
as  we  have  seen  that  it  acts  in  diffusing  light. 

*  The  effects  of  expansion,  melting,  evaporation,  the  permanent  elas- 
ticity of  gases  and  vapors,  and  many  other  phenomena,  formerly  referred 
to  the  action  of  a  peculiar  agent  called  heat,  are  now  supposed  to  be  the 
result  of  the  motion  which  the  ether-waves  communicate  to  the  material 
particles  of  the  bodies  on  which  they  strike  or  through  which  they  are 
transmitted.  To  understand  this,  we  must  remember  that  the  molecules, 
even  of  the  densest  solids,  are  supposed  to  be  separated  from  each  other 
by  comparatively  large  spaces  filled  with  ether,  through  which  the 
waves  of  heat  and  light  may  move  more  or  less  freely,  just  as  the  waves 
of  air  pass  between  the  branches  in  a  forest.  Moreover,  as  the  waves 
of  air  impart  motion  to  the  branches  of  the  trees,  and  afterwards  are 
kept  in  motion  by  the  waving  boughs,  so  also  the  material  particles  of  a 
body  may  set  in  motion  the  waves  of  ether,  or  receive  motion  from  them 
in  return. 


50  RELIGION   AND    CHEMISTRY.  [LECT.  H. 

Indeed,  this  effect  is  one  of  the  thousand  con- 
The  atmo  ditions  on  which  the  existence  of  organic 
phere  diffuses  life  depends.  Were  it  not  for  the  influence 

the  sun's  heat.         *    ,,     '  -,  ., 

of  the  atmosphere,  the  greatest  extremes 
of  temperature  would  be  produced  by  the  alterna- 
tion of  day  and  night,  and  even  were  the  density 
of  the  atmosphere  reduced  only  one  half,  the  vari- 
ation would  be  so  great  as  to  render  the  existence 
of  the  higher  forms  of  organic  life  impossible,  except, 
perhaps,  in  the  more  favored  regions  of  the  earth. 
But  not  only  does  the  atmosphere  diffuse  the 
heat  of  the  sun's  rays,  it  also  acts,  and  even  more 

effectually,  in  retaining  on  the  surface 
phere  retains  the  heat  which  the  earth  is  constantly 

receiving  from  that  great  central  luminary. 
The  atmosphere  has  been  compared  to  a  mantle, 
and  the  comparison  is  just ;  for,  like  a  huge  cloak, 
it  envelops  the  earth  in  its  folds,  and  protects  it 
from  the  chill  of  the  celestial  spaces  through  which 
we  are  rushing  with  such  frightful  velocity.  In 
order  to  understand  how  a  thin  and  transparent 
medium  like  air  can  thus  act  to  keep  the  earth 
warm,  we  must  recur  to  some  of  the  facts  estab- 
lished above. 

As  the  ether-waves,  breaking  on  the  eye  more 
or  less  rapidly,  produce  the  different  sensations  of 
Heat  of  low  and  color,  so  when  breaking  on  the  skin  they 
high  intensity.  occasion  analogous  differences  in  the  sen- 
sation of  heat,  which,  although  not  so  accurately 
distinguished,  because  the  sense  is  less  delicate, 
nevertheless  are  as  real  as  the  difference  between 


LECT.II.]  TESTIMONY   OF   THE   ATMOSPHERE.  51 

a  low  and  sweet  musical  note,  and  one  that  is  high 
and  shrill.  There  are  waves  of  heat  which  break 
upon  our  nerves  of  feeling  like  the  shrill  cry  of 
the  cricket  on  the  ear,  and  seem  to  penetrate  to 
the  very  brain,  while  there  are  others  which  fall 
like  the  low  tones  of  an  organ,  diffusing  through- 
out the  system  a  genial  glow.  Such,  for  exam- 
ple, is  the  difference  between  the  heat  from  a 
hard-coal  fire  and  that  from  a  steam  radiator. 
The  waves  of  the  first  sort,  from  their  small  size 
and  rapid  motion,  can  readily  pass  through  glass 
and  other  transparent  media,  when  the  large 
waves  with  their  slow  motion  are  in  a  great 
measure  stopped. 

Now  it  is  found  that  the  sunbeam  is  chiefly 
made  up  of  waves  of  the  first  class,  which  are 
therefore  able  readily  to  penetrate  the  atmosphere 
and  warm  the  surface  of  the  earth.  The  earth 
thus  warmed  becomes  itself  a  hot  body,  surrounded 
by  an  intensely  cold  space,  and,  like  any  other  hot 
body,  tends  to  lose  its  heat  by  radiation.  But 
the  waves  of  heat  which  the  earth*  sets  in  mo- 
tion are  of  the  second  class,  long  and  slow  undula- 
tions, and  these  are  in  great  measure  arrested  by 
the  atmosphere;  indeed,  as  experiments  have 
proved,  they  are  chiefly  absorbed  by  the  lower 
strata,  "f  in  which  we  live  and  move. 

*  The  pitch,  if  we  may  so  speak,  and  penetrating  power  of  the  heat- 
waves depend  on  the  temperature  of  the  body  by  which  they  are  set  in 
motion,  and  in  proportion  as  the  temperature  rises  the  pitch  is  higher, 
and  the  penetrating  power  greater. 

f  Professor  Tyndall  has  shown  that  this  effect  is  due  almost  entirely 


52  RELIGION   AND    CHEMISTRY.  [Lacx.  II. 

Thus  it  is  that  the  atmosphere  keeps  us  warm ; 
and  if  you  desire  further  proof  of  the  correctness 
of  these  experimental  deductions,  ascend  any  high 
mountain,  and,  as  the  thickness  of  the  aerial  cov- 
ering above  you  is  diminished  by  the  elevation, 
you  will  find  that  the  chill  increases,  vegeta- 
tion slowly  disappears,  and  before  long  you  will 
reach  a  region  of  eternal  snow  and  ice.  It  is  true 
that  there  are  other  causes  acting  to  lower  the 
temperature  at  high  elevations,  but  the  one  just 
noticed  is  by  far  the  most  important,  as  well  as 
the  primary  cause.  The  effect  of  the  atmosphere 
is  precisely  similar  to  that  of  the  glass  sashes  of 
a  hothouse.  The  glass,  like  the  atmosphere,  al- 
lows the  rapidly  undulating  waves  of  the  sun  to 
pass,*  but  almost  entirely  arrests  the  large  and 
slowly  undulating  billows,  which  radiate  from  the 
vegetation  within.  They  are  each,  in  fact,  a  trap 
to  catch  the  sunbeam. 

The  atmosphere  not  only  thus  acts  in  diffusing 
the  sun's  rays,  and  retaining  the  heat  which  they 
bring  to  us,  but  it  also  subserves  an 
e(luallv  important  end  in  distributing- 
teat,  their  genial  warmth  over  the  whole 
surface  of  the  earth,  thus  moderating  the  climate 

to  the  aqueous  vapor  in  the  atmosphere,  which  is  present  in  greatest 
quantity  in  the  strata  nearest  to  the  earth. 

*  In  the  sunbeam,  as  it  passes  through  space,  there  are  undoubtedly 
waves  of  low  pitch  in  abundance,  but  these  are  almost  entirely  arrested 
by  the  atmosphere  before  reaching  the  surface  of  the  earth.  It  has 
been  estimated  that  of  the  heat  the  earth  receives  from  the  sun  about 
one  third  is  thus  absorbed. 


LECT.  II]  TESTIMONY   OF  THE  ATMOSPHEEE.  53 

of  the  temperate  zone,  and  mitigating  the  intense 
heat  of  the  tropics.  Air,  like  all  gases,  is  ex- 
panded by  heat,  and  thus  rendered  specifically 
lighter,  and  on  this  simple  principle  all  our  meth- 
ods of  warming  and  ventilating  are  based.  When 
now  it  is  remembered  that  the  atmosphere  under 
the  tropics  must  become  more  intensely  heated 
by  the  vertical  rays  of  the  sun  than  it  is  in  the 
temperate  zones,  the  result  will  be  obvious.  The 
heated  air  rises,  and  the  cold  air  rushes  in  from  the 
north  and  south  to  take  its  place.  Thus,  two  gen- 
eral currents  are  excited  in  the  aerial  ocean  of  each 
hemisphere,  one  on  the  surface  of  the  earth  tend- 
ing towards  the  equator,  and  another,  higher  in 
the  atmosphere,  tending  towards  the  poles.  These 
currents,  however,  do  not  blow  due  north  or  south ; 
for  many  causes  combine  to  turn  them  from  their 
primitive  directions. 

In  the  first  place,  the  rotation  of  the  globe  on 
its  axis  imparts  to  objects  on  the  surface  a  motion 
from  west  to  east,  varying  in  velocity, 
from  nothing,  at  the  poles,  to  the  speed 
of  a  cannon-ball,  at  the  equator.  In  consequence 
of  this,  a  mass  of  air  moving  towards  the  equator 
is  constantly  arriving  at  a  point  on  the  surface 
of  the  earth,  which  is  moving  towards  the  east 
more  rapidly  than  the  point  it  has  just  left;  and 
as,  in  virtue  of  the  law  of  inertia,  the  moving  mass 
cannot  accommodate  itself  instantaneously  to  the 
increased  velocity,  it  is  left  a  little  behind,  —  that 
is,  a  little  to  the  west,  at  every  step.  Hence,  the 


Trade  winds. 


54  RELIGION  AND    CHEMISTRY.  [LECT.  H. 

lower  or  polar  currents  bend  more  and  more 
towards  the  west  as  they  approach  the  equator, 
acquiring  in  the  northern  hemisphere  a  south- 
westerly, and  in  the  southern  hemisphere  a  north- 
westerly direction ;  and  the  currents  of  the  two 
hemispheres,  meeting  at  the  equator,  combine  to 
produce  the  great  trade-wind,  which,  in  the  Pa- 
cific Ocean,  blows  constantly  from  the  east  to 
the  west,  and  would  blow  regularly  in  this  direc- 
tion all  round  the  globe  if  the  continents  did  not 
intervene  to  disturb  its  course  at  various  points. 

The  effect  of  the  earth's  rotation  on  the  current 
of  warm  air  which  flows  from  the  equator  in  the 
upper  atmosphere,  must  evidently  be  the  reverse 
of  that  just  described,  bending  it  constantly  to  the 
east,  and  giving  to  it  in  the  northern  hemisphere 
a  northwesterly,  and  in  the  southern  hemisphere  a 
southeasterly  direction.  But  the  upper  and  lower 
currents  do  not  long  retain  this  relative  position; 
for,  as  the  first  comes  northward,  it  gradually  Sinks, 
and,  long  before  reaching  this  latitude,  touches  the 
surface  of  the  earth.  Then,  of  course,  it  comes  in 
collision  with  the  current  from  the  north,  and  here 
a  strife  for  the  mastery  ensues.  Sometimes  the  one 
and  sometimes  the  other  prevails,  and  this  alternat- 
ing ascendency  is  one  of  the  chief  causes  which  ren- 
der the  winds  of  temperate  climates  so  irregular. 

Again,  the  unequal  heating  effect  of  the  sun's 
rays  on  the  earth,  as  compared  with  the  sea,  corn- 
causes  of  ir-  bined  with  the  irregular  distribution  of 

regularity.  ^^     ^ft    wa£er    QVer    ^6    SUrfaCC    Of    the 


LECT.  II.]  TESTIMONY   OP   THE   ATMOSPHERE.  55 

globe,  tends  to  complicate  still  farther  the  motion 
of  the  aerial  currents.  For  reasons  which  will 
hereafter  appear,  the  land  is  more  heated  by  the 
sun's  rays  than  the  sea,  when  under  the  same  con- 
ditions, and,  on  the  other  hand,  as  soon  as  the  sun 
is  withdrawn,  it  cools  more  rapidly.  Hence,  on  an 
island  in  a  warm  climate  we  generally  have,  during 
the  day-time,  a  current  of  heated  air  rising  from 
the  surface  of  the  earth,  and  a  current  of  cooler 
air  flowing  in  on  all  sides  from  the  ocean  to  take 
its  place,  while  after  sunset  the  land  soon  cools 
below  the  temperature  of  the  surrounding  ocean, 
and  the  current  is  reversed.  Thus  is  produced 
the  daily  alternation  of  land  and  sea  breezes, 
which  is  so  familiar  to  every  one  who  has  visited 
the  tropics,  where  these  phenomena  are  most 
strongly  marked. 

Quite  a  similar  reciprocal  action  between  the 
continents  and  the  great  ocean  is  caused  by  the 
alternation  of  seasons,  and  of  this  the 
monsoons  of  the  Indian  Ocean  are  a  re- 
markable illustration.  This  mediterranean  ocean, 
shut  off  from  the  influence  of  the  general  trade- 
winds  by  the  great  continental  masses  which  sur- 
round it,  has  a  system  of  aerial  currents  peculiar 
to  itself,  blowing  six  months  of  the  year  in  one 
direction  and  six  months  in  the  other.  These  are 
set  in  motion  by  the  unequal  heating  of  the  con- 
tinents of  Asia  and  Africa  during  the  extreme 
seasons.  In  the  months  of  December,  January, 
and  February,  the  part  of  Africa  south  of  the 


56  RELIGION   AND    CHEMISTRY.  [LECT.  II. 

equator  is  exposed  to  the  vertical  rays  of  a  sum- 
mer's sun,  while  the  countries  of  Southern  Asia 
are  feeling  the  comparative  cold  of  their  win- 
ter. The  natural  consequence  is,  that  a  stream  of 
cold  air  rushes  across  the  Indian  Ocean  to  feed 
the  intensely  •  heated  current  which  is  rising  over 
the  burning  plains  of  Africa,  producing  a  strong 
northeasterly  breeze,  which  is  the  winter  monsoon 
of  India.  When,  however,  the  sun  comes  north  of 
the  equator,  all  these  conditions  are  reversed.  The 
ocean  air  now  rushes  to  the  more  heated  plains 
of  India,  and  the  summer  monsoon  sets  in,  which 
blows  from  the  southwest,  the  change  from  one  to 
the  other  being  always  attended  by  variable  winds 
and  furious  storms. 

Lastly,  the  position  of  mountain  chains  and  the 
configuration  of  the  continents,  which  break  and 
turn  the  winds,  or  open  to  them  a  freer  channel, 
have  an  important  influence  in  determining  the 
direction  of  the  aerial  currents  on  the  earth.  But 
we  have  not  time  for  further  details;  they  are  given 
in  all  works  on  physical  geography,*  and  the  stu- 
dent of  natural  theology  will  find  that  subject  rich 
in  illustrations  of  God's  wisdom  and  power.  We 
have  already  become  sufficiently  acquainted  with 
the  general  plan  to  understand  how  the  atmosphere 
acts  in  equalizing  the  climate  of  the  globe.  The 
aerial  currents  which  come  to  us  from  the  south 
bring  with  them  the  heat  of  the  tropics,  and  distrib- 
ute it  over  the  temperate  zone.  As  they  blow 

*  See  "  Earth  and  Man,"  by  Professor  Arnold  Guyot. 


LECT.II.]  TESTIMONY   OF   THE   ATMOSPHERE.  57 

from  the  southwest,  they  naturally  exert  the 
greatest  heating  power  on  the  western  coasts  of 
the  continents,  and  this  is  one  great  cause  of  the 
well-known  fact  that  the  climate  of  Western  Eu- 
rope is  so  much  milder  than  our  own,  and  the  cli- 
mate of  California  and  Oregon  so  much  warmer 
than  that  of  the  corresponding  latitudes  on  the 
eastern  coast  of  Asia.  Moreover,  the  sea-breezes 
on  islands  and  along  sea-coasts,  the  monsoons  of 
the  Indian  Ocean,  and  other  local  currents,  all  com- 
bine, as  our  theory  shows,  to  produce  the  same 
general  result,  cooling  such  regions  of  the  earth 
as  from  any  cause  have  become  overheated,  and 
transferring  the  warmth  to  places  where  it  is 
more  needed.  Just  as  the  heat  of  burning  fuel  is 
diffused  over  a  whole  building  from  the  furnace  by 
the  currents  of  air  it  sets  in  motion,  so  the  sun's 
heat  is  diffused  over  the  earth  from  the  tropics  by 
the  great  terrestrial  currents  we  have  so  briefly  de- 
scribed. Indeed,  as  already  stated,  in  all  our  meth- 
ods of  heating,  we  merely  apply,  on  a  small  scale, 
the  same  general  principles  which  are  at  work 
around  us  in  the  atmosphere. 

But,  although  the  heat  of  the  sun  might  set  in 
motion  these  aerial  currents,  they  would  have  but 
little  effect  in  warming  our  northern  cli-  capacity  of  the 
mate,  were  it  not  that  the  air  has  been  «^forheat 
endowed  with  a  certain  capacity  of  holding  heat. 
All  substances  possess  this  capacity  to  a  greater  or 
less  degree,  but  the  differences  between  them  are 
very  large.  Thus  the  amount  of  heat  required  to 


58  RELIGION  AND   CHEMISTRY.  [LECT.  H. 

warm  a  pound  of  water  is  ten  times  greater  than 
would  be  required  to  raise  the  temperature  of  a 
pound  of  iron,  and  thirty  times  greater  than  would 
be  required  to  raise  the  temperature  of  a  pound 
of  mercury  to  an  equal  extent.  Hence,  under 
the  same  conditions,  a  pound  of  water  may  be 
said  to  contain  ten  times  as  much  heat  as  a  pound 
of  iron,  and  thirty  times  as  much  as  a  pound  of 
mercury;  or,  again,  in  other  words,  the  capacity 
of  water  for  heat  is  ten  times  greater  than  that  of 
iron,  and  thirty  times  greater  than  that  of  mer- 
cury. The  capacity  of  air  for  heat  is,  weight  for 
weight,  about  twice  as  great  as  that  of  iron,  and 
although  only  one  fifth  as  great  as  the  capacity 
of  water,  it  is  yet  greater  than  that  of  most 
other  substances.  The  point,  however,  to  which 
I  wish  to  direct  your  attention,  is  the  fact  that 
this  capacity  is  exactly  adjusted  to  the  office 
which  the  air  has  been  appointed  to  fill.  "Were 
the  capacity  of  the  air  less,  the  hot  air  from 
the  tropics  would  bring  to  us  proportionally  less 
heat;  were  it  greater,  the  reverse  would  be  the 
case ;  and  in  either  event,  the  distribution  of  tem- 
perature on  the  earth  would  be  changed.  To  what 
extent  such  a  change  would  affect  the  general 
welfare  of  man,  it  is  impossible  to  determine  ;  but 
when  we  consider  how  far  the  history  of  man  has 
been  influenced  by, climate,  it  will  appear  that  the 
present  distribution  of  the  human  race  —  the  exist- 
ence, for  example,  of  a  large  and  influential  city  in 
this  place,  —  may  be  said  to  depend  on  the  adjust 


LECT.IL]  TESTIMONY    OF   THE   ATMOSPHERE.  59 

ment  of  the  capacity  of  the  atmosphere  for  heat ; 
and  yet  it  depends  no  less  on  ten  thousand  other 
conditions,  many  of  them  far  more  important  than 
this.  How  truly,  then,  it  may  be  said,  that  even 
here  on  earth  we  live  in  "  a  city  which  hath  foun- 
dations, whose  builder  and  maker  is  God  " ! 

Such  are  a  few  of  the  more  obvious  marks  of 
design,  which  may  be  discovered  by  studying  the 
relations  of  the  atmosphere  to  light  and 

°4    t  Relations  of  the 

heat.  I  might  here  close  one  division  of  atmosphere  to 
my  subject;  but  I  should  fail  to  give  you 
an  adequate  idea  of  the  wonderful  play  of  physical 
forces  in  the  atmosphere,  were  I  -to  leave  out  of 
view  that  mighty  agent  which  charges  the  artillery 
of  heaven  and  feeds  the  flaming  torches  in  the 
northern  sky.  It  is  true  that  the  atmospheric  re- 
lations of  electricity  are  very  imperfectly  under- 
stood, and  the  important  ends  which  it  undoubtedly 
subserves  in  the  economy  of  nature  almost  entirely 
unknown.  We  cannot,  therefore,  expect  that  they 
will  furnish  us  with  many  additional  illustrations  of 
the  Divine  attributes ;  but  since  electrical  phenom- 
ena play  so  conspicuous  a  part  in  the  atmosphere, 
and  must  have  been  included  in  its  plan,  they  should 
not  certainly  be  overlooked  if  we  would  gain  a  gen- 
eral idea,  however  imperfect,  of  the  whole  design. 

Of  all  the  assumed  agents  of  nature  there  is  hardly 
one  which  is  so  little  understood,  and  yet  has  been 
so  carefully  studied,  as  electricity.  To  the  Nature  of  eleo_ 
uneducated  it  affords  the  convenient  expla-  tiicity' 


60  RELIGION   AND    CHEMISTRY.  [LECT.  H. 

nation  of  most  obscure  phenomena,  while  with  men 
of  science  it  is  the  object  of  much  laborious  investi- 
gation and  careful  theorizing.  The  study  of  its  phe- 
nomena has  been  fruitful  in  the  discovery  of  facts ; 
but  it  has  as  yet  led  to  but  few  general  principles, 
and  has  furnished  only  a  meagre  explanation  of 
those  grand  displays  of  nature  in  which  it  seems  to 
be  such  an  important  agent. 

In  regard  to  the  nature  of  electricity,  we  are  en- 
tirely ignorant.  The  phenomena  of  light  and  heat  * 
admit,  to  say  the  least,  of  an  intelligible  explana- 
tion, and  can  be  referred  to  a  dynamical  origin ;  but 
in  the  case  of  electricity  we  are  obliged  to  be  con- 
tent with  collecting  facts,  and  must  await  the  fur- 
ther progress  of  science  to  reveal  the  now  hidden 
cause.  I  am  well  aware  that  electricity  has  been 
regarded  as  a  very  rare  and  subtile  fluid,  and  that  this 
theory  has  not  only  afforded  a  plausible  explanation 
of  most  of  the  phenomena  of  statical  electricity,  but 
also  that  the  numerical  results  based  upon  it  have 
been  most  remarkably  verified  by  experiment.  Yet 
nevertheless,  although  the  theory  may  still  be  used 
as  a  convenient  frame  in  which  to  exhibit  the  facts, 
there  are  but  few  investigators  of  the  present  day 
who  would  claim  for  it  more  than  a  very  partial 
foundation  in  truth,  and  most  would  reject  it  alto- 
gether as  utterly  untenable. 

The  fundamental  facts  of  electricity  were  known 
to  the  ancients,  and  are  familiar  to  every  one.  If 
a  stick  of  sealing-wax  or  a  glass  tube  is  rubbed 

*  See  a  recent  work  by  Tyndall  on  Heat  as  a  Form  of  Motion. 


LECT.n.]  TESTIMONY   OF   THE  ATMOSPHERE.',  61 

V^.^  <N       * 

with  a  warm  silk  handkerchief  it  becomes,  as  we 
say,  electrified,  and  in  this  condition  has  Fundamental 
the  power  of  attracting  pieces  of  paper  facta- 
or  any  light  particles  of  matter.  When  the  scien- 
tific men  of  the  last  century  came  to  examine  these 
phenomena  more  carefully,  they  found  that  the 
handkerchief  was  also  electrified  and  thrown  into 
a  state  differing  from  that  of  the  glass  in  the 
one  case  and  that  of  the  resin  in  the  other,  very 
much  as  the  north  pole  of  a  magnet  differs  from  its 
south  pole.  They  found  also  that  the  resin  was 
electrified  oppositely  to  the  glass,  and  they  hence 
concluded  that  there  were  two  kinds  of  electricity, 
which  they  distinguished  by  the  names  resinous  and 
vitreous,  or  positive  and  negative.  They  also  dis- 
covered that  this  agent  could  readily  be  drawn  off 
from  electrified  bodies  by  the  metals,  but  only  with 
difficulty,  if  at  all,  by  such  materials  as  India-rubber, 
glass,  resin,  or  silk,  and  they  were  hence  led  to  di- 
vide substances  into  conductors  and  non-conductors 
of  electricity.  A  good  conductor,  when  insulated  by 
non-conductors,  was  found  to  retain  for  a  short  time 
the  electricity  it  had  received  from  the  electrified 
glass  or  resin,  although  the  charge  was  soon  dissi- 
pated by  the  surrounding  air,  especially  when  moist. 
By  bringing  in  the  aid  of  machinery,  and  thus  in- 
creasing the  surfaces  of  friction,  it  was  found  possible 
to  enhance  very  greatly  the  effects  obtained  with  a 
glass  tube ;  and  this  was  the  origin  of  the  electrical 
machine.  This  familiar  instrument  is  merely  a  me- 
chanical contrivance  for  rubbing  together  glass  and 


62  RELIGION   AND    CHEMISTRY.  [LECT.  IL 

silk,  with  two  insulated  metallic  conductors  for  re- 
ceiving the  two  kinds  of  electricity  thus  generated. 
If  the  hand  or  a  metallic  knob  was  brought  near  the 
prime  conductor  of  the  machine  when  highly  elec- 
trified, it  was  found  that  a  luminous  discharge  fol- 
lowed, which  was  termed  an  electrical  spark ;  and  it 
was  found  possible  by  means  of  a  glass  jar,  coated 
inside  and  outside  with  some  metallic  leaf,  called  a 
Ley  den  jar,  to  accumulate  the  two  electricities  in 
such  large  quantities  that,  when  allowed  to  flow  to- 
gether, the  discharge  was  capable  of  producing  vio- 
lent mechanical  action,  similar  to  that  of  lightning, 
although  on  a  vastly  reduced  scale.  It  was  also 
discovered  that  electricity  passes  readily  through 
the  greatly  rarefied  atmosphere  in  the  receiver  of 
an  air-pump,  causing  a  luminous  effect  similar  to  the 
aurora  borealis.  Lastly,  it  was  observed  that  elec- 
tricity readily  escapes  into  the  atmosphere  from  a 
pointed  conductor,  and,  conversely,  that  a  heavy 
charge  can  be  silently  and  harmlessly  drawn  from 
an  electrified  body  by  holding  near  it  the  point 
of  a  needle.  By  attaching  a  pointed  conductor  to 
a  boy's  kite,  Franklin  succeeded  in  drawing  an  elec- 
tric spark  from  a  thunder-cloud,  and  having  thus 
established  the  identity  between  atmospheric  and 
friction  electricity,  he  erected  the  pointed  rod,  which 
protects  our  dwellings  against  the  lightning's  stroke. 
More  recently  it  has  been  discovered  that  fric- 
tion is  by  no  means  the  only  source  of  electricity, 
and  it  seems  probable  that  no  change,  either  chem- 
ical or  physical,  takes  place  in  Nature  without  some 


LECT.II.]  TESTIMONY    OF   THE   ATMOSPHERE.  63 

manifestation  of  this  agent.  It  was  at  first  sup- 
posed that  there  were  several  kinds  of  electricity, 
which  were  named  thermo-electricity,  magneto- 
electricity,  voltaic  electricity,  and  animal  electricity, 
according  to  the  nature  of  the  process  in  which 
the  electrical  action  was  developed ;  but  it  is 
now  universally  conceded  that  all  are  only  differ- 
ent manifestations  of  the  same  agent,  and  most 
investigators  believe  that  electricity  will  in  time  be 
shown  to  be  a  form  of  molecular  motion  analogous 
to  that  which  produces  the  phenomena  of  light 
and  heat,  although  it  has  not  as  yet  been  found  pos- 
sible to  frame  a  comprehensive  and  intelligible  the- 
ory based  upon  this  hypothesis.  Again,  it  has  been 
found  that  friction  is  a  far  more  general  source  of 
electricity  than  was  at  first  believed.  In  fact,  elec- 
trical phenomena  appear  to  be  a  constant  result  of 
friction,  whatever  may  be  the  nature  of  the  sub- 
stances rubbed.  Thus  it  is  developed  by  blowing 
air  over  glass,  and  the  hydro-electric  machine,  one 
of  the  most  effective  means  of  generating  electricity 
we  possess,  owes  its  surprising  energy  to  the  friction 
of  globules  of  water  against  the  sides  of  the  vent- 
cock  of  a  steam-boiler.* 

When,  now,  we  consider  that  the  air  is  always 
f  ubbing  over  the  surface  of  the  earth,  at  times  with 

*  This  machine  consists  simply  of  a  small  steam-boiler  insulated  on 
glass  pillars,  having  a  peculiarly-constructed  vent-cock  and  provided 
with  suitable  metallic  conductors  for  receiving  the  electricity.  The 
steam,  as  it  escapes  under  high  pressure,  becomes  filled  with  globules  of 
water  which  rub  against  the  sides  of  the  vent-tube,  and  this  is  so  shaped 
as  to  facilitate  their  formation. 
5 


64  KELIGION   AND    CHEMISTRY.  [LECT.  H. 

great  rapidity,  we  shall  not  be  surprised  to  learn 
Atmospheric  that  both  bodies  are  constantly  in  an 
electricity.  electrified  condition,  the  earth  being  gen- 
erally charged  negatively,  and  the  atmosphere  posi- 
tively. Even  in  fair  weather  it  is  always  possible 
to  detect  the  presence  of  free  electricity  in  the 
atmosphere ;  and  during  a  storm,  when  clouds  filled 
with  vesicular  drops  of  water  are  hurried  over  the 
surface,  grinding  against  the  hills  and  the  trees,  or 
against  each  other,  the  atmosphere  becomes  a  vast 
hydro-electric  machine,  whose  sparks  are  the  light- 
ning, and  the  noise  of  its  discharges  the  thunder. 
Again,  the  various  chemical  and  physical  changes 
which  are  going  on  around  us,  —  such  as  the  vital 
processes  of  animals  and  plants,  the  combustion  of 
fuel,  volcanic  action,  the  evaporation  of  water,  —  all 
undoubtedly  add  to  the  electrical  excitement  of  the 
atmosphere,  and  more  or  less  modify  the  result.  It 
is  not  important  for  us,  however,  to  study  the 
action  of  each  one  of  these  causes ;  for  we  have, 
probably,  in  the  friction  of  moist  air  driven  by  the 
winds,  the  chief  source  of  atmospheric  electricity; 
and  when  we  consider  the  amount  of  friction  which 
must  attend  the  rapid  motion  of  storm-clouds,  or  of 
a  tornado  through  the  atmosphere,  the  wonder  is, 
not  that  an  occasional  thunderbolt  should  kindle  a 
conflagration,  or  even  cause  a  death,  but  that  every 
storm  does  not  lay  waste  the  earth  along  its  fiery 
track.  Moreover,  when  we  appreciate  the  vastness  of 
the  scale  on  which  the  electrical  machine  of  nature 
is  constructed,  the  thunder-storm  ceases  to  surprise 


LECT.II.]  TESTIMONY   OF   THE   ATMOSPHERE.  65 

us,  and  only  calls  our  attention  to  those  beneficent 
provisions  by  which  we  and  our  race  are  saved  by 
a  constant  miracle  from  the  fate  of  the  cities  of 
the  plain.  That  the  atmospheric  electricity  was 
designed  to  subserve  many  important  and  benefi- 
cent ends,  the  whole  analogy  of  nature  compels  us 
to  believe ;  but  while  our  present  ignorance  con- 
ceals them  from  our  sight,  we  may  still  discover 
evidence  of  God's  goodness  and  wisdom  in  those 
simple  provisions  by  which  the  atmosphere  is  pre- 
served from  violent  or  frequent  electrical  excite- 
ment, and  its  charge  drawn  down  harmlessly  to  the 
earth. 

Since  the  atmosphere  is  at  best  a  very  poor  con- 
ductor, the  electricity  developed  by  the  processes 
iust  considered  tends  to  accumulate,  and 

7  Protection 

under  peculiar  conditions  the  clouds  may  against  nght 
become  so  highly  charged,  that  at  length  nmg' 
the  pent-up  power  acquires  sufficient  force  to  break 
through  all  barriers,  and  the  lightning  dashes  to 
the  earth,  crashing,  rending,  and  burning  on  its 
way.  To  guard  his  roof  from  its  destructive  action, 
man  erects  the  lightning-rod,  whose  bristling  points 
quietly  drain  the  clouds,  or,  failing  to  do  this,  re- 
ceive the  charge,  and  bear  it  harmlessly  to  the 
earth.  But  ages  before  Franklin  pointed  the  first 
rod  to  the  storms,  the  merciful  Parent  of  mankind 
had  surrounded  the  dwellings  of  his  children  with 
a  protection  far  more  effectual  than  this ;  for,  since 
the  creation  of  organic  life,  every  pointed  leaf, 
every  twig,  and  every  blade  of  grass  have  been 


66  RELIGION   AND    CHEMISTRY.  [LECT.  II. 

silently  disarming  the  clouds  of  their  destructive 
weapon.  It  is  difficult  to  improve  upon  nature, 
and  man  constantly  finds  that  in  his  best  inventions 
he  has  been  anticipated  from  eternity  by  a  greater 
Inventor  than  he.  So  not  long  after  Franklin  had 
discovered  the  efficacy  of  metallic  points  in  dis- 
sipating a  charge  of  electricity,  and  had  applied 
the  principle  in  constructing  the  lightning-rod,  it 
was  found  that  a  common  blade  of  grass  pointed 
with  nature's  exquisite  workmanship  was  three 
times  as  effectual  as  the  finest  cambric  needle,  and 
a  single  twig  far  more  efficient  than  the  metallic 
points  of  the  best-constructed  rod.  When,  now, 
you  reflect  how  many  thousand  of  these  vegetable 
points  every  large  tree  directs  to  the  sky,  and  con- 
sider what  must  be  the  agency  of  a  single  forest 
with  its  innumerable  twigs,  or  of  a  single  meadow 
with  its  countless  blades  of  grass,  and  then  when 
you  remember  that  these  are  only  subsidiary  to 
those  vast  lightning-conductors,  the  mountain- 
chains,  whose  craggy  summits  pierce  the  clouds 
themselves,  and  still  further,  when  you  learn  that 
the  rain-drops  and  snow-flakes  have  been  made 
good  conductors,  so  that  during  the  storms  a  bridge 
for  the  lightning  is  thrown  across  from  the  clouds 
to  the  earth,  you  will  see  how  abundant  the 
protection  is,  and  with  what  care  Providence  has 
guarded  us  from  the  destructive  agent.  It  is 
only  under  unusual  circumstances,  when  electrici- 
ty is  developed  more  rapidly  than  it  can  be  dis- 
sipated through  these  numberless  channels,  that 


LECT.H.]  TESTIMONY    OF   THE  ATMOSPHERE.  67 

a  violent  discharge  takes  place,  and  if  then  it  tears, 
burns,  or  kills,  it  also  reveals  the  Merciful  Hand 
which  constantly  spares.  Moreover,  through  this 
servant  of  his  pleasure,  God  is  constantly  educating 
and  elevating  his  creatures.  In  the  wild  corsus- 
cations  of  the  lightning,  and  in  the  reverberating 
roll  of  the  thunder,  Nature  exhibits  one  of  her 
grandest  aspects,  before  which  man  is  awed  and 
terrified,  while  he  admires  afid  adores;  and  also 
when,  through  the  cold,  dry  air  of  the  arctic  region 
the  electric  charges  shoot  down  to  the  earth  in 
tremulous  flashes,  then  Nature  lights  up  her  grand 
displays  of  northern  fires,  which  enliven  the  long 
night  of  the  arctic  winter,  or  in  this  more  favored 
climate  excite  the  curiosity  and  call  forth  the  ad- 
miration of  all.* 

I  must  here  conclude  this  very  imperfect  sketch 
of  the  physical  adaptations  of  the  atmosphere  to 
the  ends  it  subserves  on  the  earth.     We  Distinctive 
studied  in  the  first  place  its  aeriform  con-  marksofthe 

*  design  of 

dition,  and  found  that  its  density  not  only  nature. 
forms  an  essential  part  of  the  scheme  of  organic  na- 
ture, but  also  is  closely  related  to  the  dimensions  of 
the  solar  system.  In  this  Lecture  we  have  studied 
the  relations  of  the  atmosphere  to  light,  heat,  and 
electricity ;  and  although  we  have  been  able  only  to 
glance  at  some  of  the  more  prominent  features  in 

*  I  am  indebted  for  many  of  the  above  illustrations  to  an  admirable 
paper  on  atmospheric  electricity  in  the  American  Almanac  for  1854,  by 
my  friend  and  colleague,  Prof.  Joseph  Lpvering, 


68  RELIGION  AND    CHEMISTRY.  [LECT.  IL 

these  wonderful  displays  of  creative  energy,  we  have 
found,  wherever  we  turned,  abundant  illustrations 
of  the  wisdom,  power,  and  goodness  of  our  God.  I 
trust  that  you  have  been  impressed  by  the  vastness, 
the  complexity,  and  yet  the  simplicity  and  harmony 
of  the  whole  design,  for  these  are  the  chief  points 
which  I  have  endeavored  to  set  forth.  But  0  how 
imperfect  any  conception  which  I  can  give  you 
must  be !  This  atmosphere  is  sustained  in  the 
proper  working  of  all  its  parts  only  by  the  exact 
balancing  of  a  thousand  conditions.  Attempt  to 
make  yourself  acquainted  with  these  conditions, 
and,  disregarding  those  which  you  recognize  at 
once  as  surpassing  human  intelligence,  study  only 
such  as  are  thoroughly  understood  and  universally 
admitted  to  have  been  primary  conditions  in  the 
plan  of  nature  before  the  atmosphere  could  exist 
as  it  is.  This  is  not  an  impossible  task.  It  would 
require  years  of  study,  and  it  would  lead  you  into 
every  department  of  physical  science,  but  the  result 
would  well  repay  your  labor.  You  would  find  it 
easy  to  follow  out  any  one  line  of  the  conditions, 
until  it  became  lost  in  the  obscurity  of  the  unknown ; 
but  to  form  a  conception  of  the  simultaneous  work- 
ing of  all  in  their  varied  relations,  or  even  of  two  or 
three,  you  would  soon  discover  to  be  a  hopeless  task. 
The  complication  of  this  wonderful  machinery  so  far 
transcends  man's  mental  power,  that  to  understand 
its  combined  action  is  simply  impossible.  But  al- 
though you  would  thus  be  made  most  keenly  sensi- 
ble of  the  limits  of  your  human  powers,  you  would 


LECT.  II.]  TESTIMONY   OP   THE   ATMOSPHERE.  69 

also  be  filled  with  gratitude  for  the  great  privilege 
you  enjoyed  of  studying  this  divine  mechanism, 
even  if  you  could  understand  its  workings  only 
obscurely  and  in  part. 

Paley  has  compared  the  mechanism  of  nature  to 
a  watch,  and,  so  far  as  the  argument  for  design  is 
concerned,  the  analogy  is  perfect.  We  must  never 
forget,  however,  that  there  is  an  essential  difference 
between  the  scheme  of  nature  and  the  most  compli- 
cated human  mechanism.  I  have  seen  a  carpet- 
loom  weaving  a  pattern  composed  of  twelve  differ- 
ent colors,  and,  as  I  watched  the  shuttles  of  various 
colored  yarns  which  were  selected  by  the  hands  of 
the  machine  with  unerring  certainty,  and  thrown 
through  the  warp,  it  seemed  as  if  the  very  iron  were 
endowed  with  intelligence,  and  the  impression  was 
one  of  wonder  and  bewilderment.  To  comprehend 
such  complexity  appeared  impossible ;  but  the  more 
I  studied  the  details  of  the  machine,  the  more  thor- 
oughly I  understood  the  mode  of  its  action,  until  at 
last  the  wonder  vanished ;  and  although  not  ceas- 
ing to  admire  the  skill  of  the  inventor,  I  felt  I  had 
comprehended  the  whole,  and  could  even  conceive 
of  the  mental  process  by  which  such  a  wonderful 
combination  of  means  had  been  made  and  adjusted 
to  produce  the  desired  end.  The  artist  was  inge- 
nious, but  the  machine  was  still  human. 

How  different  it  is  with  the  mechanism  of  na- 
ture !  Here,  also,  it  is  true,  the  more  we  study,  the 
more  we  understand  the  workmanship ;  but  then 
we  never  reach  the  limit.  The  more  our  powers  of 


70  RELIGION   AND    CHEMISTRY.  [LEGT.  II. 

thought  and  observation  are  developed,  and  the 
more  our  experience  is  enlarged,  the  more  the  field 
of  possible  knowledge  expands  before  us.  The  lar- 
ger our  attainments,  the  less  we  seem  to  know. 

We  still  recognize  the  unmistakable  marks  of 
intelligence  in  the  design,  but  it  is  no  longer  an 
intelligence  we  can  fathom ;  we  feel  that  it  is  infi- 
nitely above  us :  in  a  word,  we  feel  that  it  is  God 
Would  that  my  feeble  language  might  convey  to 
you  the  full  power  of  this  impression  ;  for  until  you 
are  conscious  of  the  infinite  beauty  and  skill  with 
which  the  numberless  parts  of  nature  have  been 
fashioned  and  adjusted,  you  cannot  appreciate  the 
force  of  the  conviction  which  the  impression  gives. 
You  may  make  yourselves  familiar  with  the  dimen- 
sions of  Mont  Blanc ;  you  may  read  the  most 
glowing  descriptions  of  this  monarch  of  mountains, 
heightened  by  all  the  arts  of  eloquence  or  of  poetry ; 
you  may  cross  the  ocean  and  travel  to  the  beauti- 
ful valley  of  Chamouni  at  its  base ;  you  may  even 
climb  its  side,  study  its  glaciers,  and  cross  its  fields 
of  snow  :  but  you  will  form  no  adequate  conception 
of  its  grandeur,  until,  ascending  one  of  the  lofty 
mountain-peaks  which  surround  it,  you  see  its 
summit  still  towering  above  your  head,  apparently 
higher  than  before.  So  it  is  in  the  study  of  nature. 
No  description  can  give  you  an  adequate  conception 
of  the  impression  which  it  leaves  upon  the  mind. 
It  is  not  until,  after  long  study,  the  student  has 
become  thoroughly  acquainted  with  some  one  por- 
tion, however  limited,  of  its  wonderful  economy, 


LECT.  II. ]  TESTIMONY   OF   THE   ATMOSPHERE.  71 

that  he  begins  to  appreciate  the  perfection  of  its 
parts,  the  infinite  skill  with  which  all  have  been 
adjusted,  and  the  true  grandeur  of  the  whole. 

By  most  men  these  heights  of  knowledge  are 
unattainable.  Why,  then,  should  we  hesitate  to-- 
receive  the  evidence  of  a  philosopher  like  Newton, 
who,  after  spending  a  long  life  in  the  investigation 
of  nature,  and  with  a  success  unparalleled  in  the 
history  of  science,  uttered  this  memorable  senti- 
ment shortly  before  his  death :  "  I  do  not  know 
what  I  may  appear  to  the  world ;  but  to  myself  I 
seem  to  have  been  only  like  a  boy  playing  on  the 
sea-shore,  and  devoting  myself  now  and  then  to 
finding  a  smoother  pebble  or  a  prettier  shell  than 
ordinary,  while  the  great  ocean  of  truth  lay  all  un- 
discovered before  me."  I  know  this  sentiment  has 
been  so  often  repeated  as  to  seem  trite,  but,  coming 
from  whom  it  does,  it  cannot  be  too  often  quoted. 
It  is  the  testimony  of  the  greatest  master  of  science 
to  its  greatest  and  sublimest  truth. 

We  can  all  recognize  the  marks  of  design  in 
nature,  and  when  we  add  to  this  evidence  of  our 
senses  the  testimony  of  a  man  like  Newton,  who 
assures  us  that  the  more  our  powers  are  enlarged, 
and  the  wider  our  knowledge  becomes,  the  grander 
and  vaster  the  design  will  appear,  until  it  surpasses 
all  our  powers  of  thought  or  imagination,  we  begin 
to  feel  the  full  depth  of  the  truth  I  have  been  en- 
deavoring to  enforce.  If  our  minds  are  incapable 
of  comprehending  the  plan,  who  could  have  been 
equal  to  the  design  ?  "  Whence,  then,  cometh  wis- 


72  KELIGION   AND    CHEMISTRY.  [LECT.  II. 

"dom,  and  where  is  the  place  of  understanding, 
"seeing  it  is  hid  from  the  eyes  of  all  living,  and 
"  kept  close  from  the  fowls  of  the  air  ?  God  under- 
"  standeth  the  way  thereof,  and  he  knoweth  the 
"  place  thereof.  For  he  looketh  to  the  ends  of  the 
"  earth,  and  seeth  under  the  whole  heaven,  to  make 
"  the  weight  for  the  winds  and  a  way  for  the  light- 
"  ning  of  the  thunder.  Then  did  he  see  it  and  de- 
K  clare  it ;  he  prepared  it,  yea,  and  searched  it  out. 
u  And  unto  man  he  said,  Behold  the  fear  of  the  Lord, 
"  that  is  wisdom,  and  to  depart  from  evil  is  under- 
"  standing." 


LECTUKE    III. 

TESTIMONY   OF   OXYGEN. 

WERE  we  to  limit  our  regards  to  those  physical 
qualities  of  the  atmosphere  which  we  studied  in 
the  first  two  Lectures,  we  should  overlook  the 
most  wonderful  adaptations  in  its  divine  economy. 
These  properties  belong  to  the  atmosphere,  in 
great  measure  at  least,  in  virtue  of  its  aeriform 
condition,  and,  so  far  as  we  know,  an  atmosphere 
composed  of  other  gases,  and  still  having  the  same 
density,  would  soften  the  intensity  of  the  light,  and 
diffuse  the  genial  influences  of  the  sun's  heat,  as 
well  as  air.  Not  so,  however,  with  the  chemical 
qualities  of  the  atmosphere,  which  we  are  next  to 
consider.  These  belong  to  the  atmosphere  solely 
as  air,  and  could  not  have  been  obtained  with  any 
other  known  materials. 

When  a  chemist  wishes  to  investigate  the  nature 
of  a  new  substance,  his  first  step  is  to  analyze  it. 
Let  us,  therefore,  as  a  preliminary  to  our  composition 
present  inquiry,  ascertain  what  is  the  com-  of  air> 
position  of  this  aeriform  matter  we  call  air.     The 
air  has  been  analyzed  hundreds  of  times  in  every 
latitude  and  in  every  climate ;  and  the  result  has 
been  uniformly  that  which  is  given  in  the  follow- 
ing table :  — 


74  RELIGION   AND    CHEMISTRY.  [LECT.  IH. 

Composition  of  the  Atmosphere.* 

Oxygen  20.61 

Nitrogen  77.95 

Carbonic  Acid  .04 

Aqueous  Vapor  (average)             1.40 

Nitric  Acid  "\ 

Ammonia  v      traces. 

Carburetted  Hydrogen  I 

100.00 

Composition  in  Tons. 

Oxygen  1,233,010  billions  of  tons. 

Nitrogen  3,994,593  -     «        " 

Carbonic  Acid  5,287 

Aqueous  Vapor  54,460 

Besides  oxygen  and  nitrogen  gases,  which,  as  you 
will  notice,  are  the  chief  constituents,  there  are  al- 
ways present  in  the  atmosphere  the  vapor  of  water, 
carbonic  acid,  and  ammonia  gas  ;  and  if  we  add  to 
these  uniform  constituents  the  various  exhalations 
constantly  arising  from  the  earth,  we  shall  have  as 
accurate  an  idea  of  the  composition  of  the  air  as 
chemistry  can  give.  While,  however,  the  propor- 
tions of  oxygen  and  nitrogen  are  almost  absolutely 
constant,  those  of  the  other  ingredients  are  very 
fluctuating,  and  the  total  quantity  exceedingly 
small,  never  amounting  in  all,  exclusive  of  aqueous 
vapor,  to  more  than  one  part  in  a  thousand,  unless 
in  some  confined  locality,  and  under  very  unusual 
circumstances.  Do  not,  however,  measure  the  im- 

*  Miller's  Elements  of  Chemistry. 


LECT.HI.]  TESTIMONY   OF   OXYGEN.  75 

portance  of  these  variable  and  in  a  degree  acci- 
dental constituents  by  their  amount,  for,  although 
present  in  such  small  quantities,  they  are  not  less 
essential  in  the  atmosphere  than  the  two  gases 
which  make  up  almost  its  entire  mass. 

Moreover,  we  must  carefully  avoid  the  error  of 
considering  air  as  a  distinct  substance,  like  water 
or  coal.  On  the  contrary,  it  is  merely  a  mechani- 
cal mixture  of  its  constituent  gases,  and  is  in  no 
sense  a  definite  chemical  compound.  Indeed,  we 
may  regard  the  globe  as  surrounded  by  at  least 
three  separate  atmospheres,  —  one  of  oxygen,  one 
of  nitrogen,  and  one  of  aqueous  vapor,  —  all  exist- 
ing simultaneously  in  the  same  space,  yet  each  en- 
tirely distinct  from  the  other  two,  and  only  very 
slightly  influenced  by  their  presence.  To  each  of 
these  atmospheres  the  Author  of  nature  has  as- 
signed separate  and  different  functions.  They  are 
like  so  many  servants  in  a  household,  each  with 
its  distinct  set  of  duties,  which  they  discharge  with 
a  fidelity  and  diligence  unknown  to  any  earthly 
service.  Let  us  consider  what  those  duties  are, 
and  see  how  skilfully  each  is  adapted  to  the  offices 
which  it  is  designed  to  fill. 

Were  all  the  other  constituents  of  the  air  re- 
moved, the  earth  would  still  be  surrounded  by  an 
atmosphere  of  oxygen,  having  about 'one  fifth  of 
the  density,  and  exerting  at  the  surface  of  the 
globe  about  one  fifth  of  the  pressure,  of  the  pres- 
ent atmosphere.  In  studying  the  chemical  rela- 
tions of  air,  let  us  begin  with  some  of  the  more 


76  RELIGION   AND    CHEMISTRY.  [LECT.  HI. 

important  functions  of  this  remarkable  substance, 
and  these  will  fully  occupy  our  time  during  this 
and  the  next  succeeding  Lecture. 

It  is  easy  to  prepare  oxygen  in  a  pure  state.  It 
is  then  a  perfectly  colorless  and  transparent  gas, 
properties  of  an^  so  persistently  does  it  retain  its  aeri- 
oxygen.  form  condition,  that  man  has  not  been 
able,  by  the  greatest  pressure  he  can  exert,  or  by 
the  greatest  degree  of  cold  he  can  artificially  pro- 
duce, to  reduce  it  to  the  liquid  or  solid  state.  A 
German  chemist,  Natterer,  submitted  this  gas  to  the 
combined  action  of  intense  cold  and  a  pressure  of 
over  forty-five  thousand  pounds,  or  twenty  tons, 
on  a  square  inch,  but  he  did  not  succeed  in  chang- 
ing its  condition.  This  is  quite  an  exceptional  fact 
in  nature.  Almost  all  aeriform  substances,  when 
submitted  to  the  action  of  great  cold,  are  con- 
densed to  liquids,  and  many  of  these  liquids  have 
been  frozen  ;  but  oxygen  and  nitrogen  are  an  ex- 
ception to  the  rule,  and  persistently  retain  their 
aeriform  condition  under  the  widest  variations  of 
temperature  which  exist  on  the  earth.  The  im- 
portance of  this  fact  will  be  seen  at  once  on  com- 
Parmg  the  condition  of  the  oxygen  and 


of  its  aeriform    nitrogen  in  the  atmosphere  with  that  of 

condition.  ,     ,  .       n  ..,         p 

the  aqueous  vapor.  A  fall  of  tempera- 
ture of  only  a  few  degrees  will  generally  con- 
dense a  portion  of  the  vapor,  and,  small  as  is  its 
relative  amount,  the  resulting  rain  is  at  times 
poured  down  upon  the  earth  in  deluging  floods  ; 


LECT.IH.]  TESTIMONY   OF   OXYGEN.  77 

and  if  you  consider  what  must  have  been  the  de- 
structive results  had  the  whole  mass  of  the  atmos- 
phere been  liable  to  a  similar  fluctuation,  even  under 
extreme  conditions,  you  will  discover  in  the  perma- 
nency of  oxygen  a  most  obvious  adaptation  of  its 
properties  to  the  thermal  condition  of  our  globe. 

The  permanently  aeriform  state  of  oxygen  will 
appear  still  more  remarkable  when  we  consider 
how  largely  it  enters  into  the  composition  of  the 
solid  crust  of  the  earth.  Oxygen  belongs  to  that 
class  of  substances  which  the  chemists  call  elements, 
because  they  have  never  succeeded  in  resolving 
them  into  simpler  parts,  and  of  all  the  elements 
it  is  by  far  the  most  widely  diffused.  As  we  have 
already  seen,  one  fifth  of  the  volume  of  the  atmos- 
phere consists  of  this  gas ;  but  this  is  a  small  amount 
compared  with  that  which  enters  into  the  composi- 
tion of  most  substances:  You  may  be  surprised  at 
the  statement,  but  it  is  nevertheless  true,  that  be- 
tween one  half  and  one  third  of  the  crust  of  this 
globe  and  of  the  bodies  of  its  inhabitants  consists 
of  oxygen.  No  less  than  eight  ninths  of  all  water  is 
formed  of  the  same  gas.  It  makes  up  three  fourths 
of  our  own  bodies,  not  less  than  four  fifths  of  every 
plant,  and  at  least  one  half  of  the  solid  rocks.  Ke- 
membering  now  that  twenty  tons  of  pressure  on  a 
square  inch  are  not  sufficient  to  reduce  oxygen  to  a 
liquid  condition,  consider  what  must  be  the  strength 
of  that  force  which  holds  it  thus  imprisoned.  Why, 
in  this  tumbler  of  water  there  are  no  less  than  six 
cubic  feet  of  oxygen  gas,  condensed  to  a  liquid  con- 


78  RELIGION   AND    CHEMISTRY.  [LECT.  IE. 

dition,  and  held  there  by  the  continuous  action  of 
a  force  which  can  be  measured  only  by  hundreds  of 
tons  of  pressure.  We  call  the  force  chemical  affin- 
ity ;  but  who  shall  measure  its  power  ?  Who  but 
He  who  could  make  with  such  a  subtile  material  the 
rocks,  with  which  he  "  laid  the  foundations  of  the 
earth,"  and  the  waters  which  roll  over  its  surface  ? 

Oxygen  gas,  like  all  other  forms  of  aeriform  mat- 
ter, tends  to  expand,  and  can  be  prevented  from 
obeying  this  natural  tendency  only  by  en- 
closing it  in  an  air-tight  receiver.  As  it 
exists  in  our  glass  jars,  under  the  ordinary  condi- 
tions of  temperature  and  pressure,  one  cubic  foot  of 
oxygen  weighs  590.8  grains,  although  in  its  more 
expanded  state,  as  it  exists  in  the  atmosphere  at 
the  surface  of  the  globe,  it  has  but  one  fifth  of  this 
density.  One  cubic  foot  of  nitrogen  gas  weighs, 
under  the  same  circumstances,  517.5  grains ;  but 
although  there  is  such  a  decided  difference  between 
the  specific  gravities  of  the  two  gases,  yet  so  per- 
fectly are  they  mixed  together  throughout  the 
whole  extent  of  the  atmosphere,  that  analysis  has 
been  unable  to  detect  the  slightest  difference  in 
composition  between  the  air  brought  from  the  sum- 
mits of  the  Alps  and  that  from  the  deepest  mine  in 
Cornwall.  Why,  you  may  ask,  do  not  these  gases 
obey  the  well-known  laws  of  hydrostatics,  the  heav- 
ier oxygen  sinking  to  the  surface  of  the  earth,  and 
the  lighter  nitrogen  floating  above  it  ?  Simply  be- 
cause gases,  unlike  the  other  forms  of  mat- 
ter, have  the  property  of  diffusing  through 


LECT.IH.]  TESTIMONY   OF   OXYGEN.  79 

each  other,  and  existing  together  in  the  same  space. 
The  presence  of  one  gas  does  not  prevent  the  en- 
trance of  another  into  the  space  which  it  occupies, 
and  if  two  open  jars,  containing  different  gases, 
are  placed  together,  mouth  to  mouth,  each  gas  will 
expand  until  it  fills  the  whole  volume.  Moreover, 
the  greater  the  difference  between  the  densities  of 
the  gases,  and  the  greater  the  consequent  tendency 
to  separate,  the  stronger  is  the  force  by  which  they 
are  compelled  to  mix  together.  This  force  is  called 
the  force  of  diffusion,  and  it  has  been  adjusted  with 
great  nicety  in  the  plan  of  creation.  Were  this 
force  in  the  atmosphere  much  less  than  it  is,  the 
two  gases  composing  air  would  have  separated  par- 
tially, and  the  atmosphere  have  become  unfitted  for 
many  of  its  important  functions.  Take,  for  example, 
the  function  of  transmitting  sound. 

As  the  air  is  now  constituted,  there  is  a  constancy 
of  pitch,  however  far  sound  travels.  Any  tone  once 
generated  remains  the  same  tone  until  it  dies  away. 
Its  degree  of  loudness  alters  in  proportion  to  the 
distance  of  the  listener,  but  the  pitch  is  constant. 
Were  it  not,  however,  for  this  law  of  diffusion, — 
were  the  atmosphere  not  perfectly  homogeneous, 
and  the  gases  of  which  it  consists  even  partially 
separated,  —  there  would  have  been  a  very  different 
result.  The  constancy  of  pitch  could  no  longer  have 
been  depended  upon.  The  sound  as  it  travelled 
would  vary  its  pitch  with  the  ever-varying  medium 
through  which  it  passed,  and  would  arrive  at  the 
ear  with  a  tone  entirely  different  from  that  with 

6 


80  KELIGION   AND    CHEMISTRY.  [LECT.  III. 

which  it  started..  Nor  would  it  require  any  great 
difference  in  the  medium  to  produce  a  sensible  re- 
sult, and  to  confuse  all  those  delicate  differences  of 
pitch  on  which  the  whole  art  of  music  depends. 
Whenever,  therefore,  you  may  be  next  enjoying 
the  grand  Pastoral  Symphony  of  Beethoven  or  the 
Eequiem  of  Mozart,  recall  the  careful  adjustment  of 
forces  by  which  alone  these  magnificent  creations 
of  genius  were  rendered  possible,  and  you  cannot 
fail  to  recognize  in  this  simple  law  of  nature  the 
same  hand  which  first  strung  the  lyre  and  made  the 
soul  of  man  responsive  to  its  seven  notes. 

Eeturning  again  to  the  qualities  of  oxygen,  let 
us  notice,  in  the  next  place,  that  it  is  entirely  desti- 
tute either  of  odor  or  of  taste.     This  fact 

Passive  and 

active  condi-  is  a  matter  of  common  experience  ;  for  as 
oxygen  exists  in  a  free  state  in  the  atmos- 
phere, it  would  there  manifest  these  properties  did 
they  exist :  and  reflect  how  essential  these  negative 
qualities  are  to  our  comfort  and  well-being.  More- 
over, in  its  ordinary  condition,  oxygen  seems  en- 
tirely devoid  of  any  active  properties.  It  does  not 
affect  the  most  delicate  and  evanescent  vegetable 
dyes,  which  the  weakest  chemical  agents  will  either 
alter  or  destroy.  And  consider  the  oxygen  as  it 
exists  in  the  air.  How  bland  and  seemingly  in- 
active it  is  there !  Eeflect  that  it  bathes  the 
most  delicate  animal  organism,  that  it  pervades 
the  minutest  air-passages  of  the  lungs,  —  remember 
that  it  is  in  contact  with  all  matter,  —  and  every 
substance  will  seem  to  bear  evidence  to  the  fact 


LECT.  III.]  TESTIMONY   OF   OXYGEN.  81 

that  oxygen  in  the  state  of  gas  possesses  no  active 
properties,  and  is  incapable  of  manifesting  any 
strong  chemical  force.  And  yet,  if  you  infer  that 
oxygen  always  appears  in  this  passive  condition, 
and  is  under  all  circumstances  incapable  of  violent 
action,  you  will  be  entirely  deceived ;  for  so  far 
from  being  one  of  the  weakest,  it  is  the  strongest  of 
the  chemical  elements,  and  beneath  this  apparent 
mildness  there  is  concealed  an  energy  so  violent, 
that,  when  once  thoroughly  aroused,  nothing  can 
withstand  it.  A  single  spark  of  fire  will  change 
the  whole  character  of  this  element,  and  what  was 
before  inert  and  passive  becomes  in  an  instant  vio- 
lent and  irrepressible.  The  gentle  breeze  which 
was  waving  the  corn  and  fanning  the  browsing 
herds,  becomes  the  next  moment  a  consuming 
fire,  before  which  the  works  of  man  melt  away 
into  air. 

And  here  I  must  correct  an  erroneous,  although 
very  common  impression,  that  there  is  something 
substantial  in  fire.  This  is  one  of  those 

.,  ....  .  .,,  «     .,         Nature  of  fire. 

ideas,  originating  in  an  illusion  01  the 
senses,  which  we  have  inherited  from  a  more  igno- 
rant age,  and  which  our  modern  science  cannot 
wholly  dispel  from  the  popular  mind.  Fire  was 
formerly  regarded  as  one  of  the  elementary  forms 
of  matter,  and  all  burning  was  supposed  to  consist 
in  the  escape  of  this  principle  of  fire,  previously 
pent  up  in  the  combustible  substance.  In  support 
of  this  doctrine  the  old  philosophers  confidently 
pointed  at  flame  as  the  visible  manifestation  of 


82  RELIGION   AND    CHEMISTRY.  [LECT.  III. 

the  escaping  fire-element.  And,  childish  as  this 
doctrine  may  seem,  it  was  the  prevalent  belief  of 
the  world  for  at  least  two  thousand  years. 

The  last  phase  which  this  doctrine  assumed  was 
the  phlogiston  theory  of  the  last  century.  In  the 
hands  of  Bergmann  and  Stahl,  the  vague  ideas  of 
the  time  received  a  more  material  form,  and  were 
embodied  in  a  philosophical  system.  They  termed 
the  principle  of  fire  phlogiston,  and  burning,  or  the 
escape  of  fire,  dephlogistication,  and  their  ingenious 
system  did  not  a  little  to  retard  the  progress  of 
truth.  It  never  seems  to  have  occurred  to  the 
philosophers  of  that  age  to  weigh  the  results  of 
burning,  or  if  they  did  by  accident,  they  most 
blindly  ignored  the  result,  and  it  was  not  until 
1783,  when  the  true  theory  of  combustion  was  dis- 
covered, that  modern  chemistry  began.  The  for- 
tunate discoverer  was  Lavoisier.  He  proved,  by 
simply  weighing  the  products  of  combustion,  that 
burning,  instead  of  being  a  loss  of  phlogiston,  is  a 
union  of  the  burning  substance  with  the  oxygen 
of  the  air,  and  this  theory  is  now  one  of  the  best 
established  principles  of  science. 

Burning  is  merely  chemical  change,  and  all  com- 
bustion with  which  we  are  familiar  in  common  life 
is  a  chemical  combination  of  the  burning  sub- 
stance, whether  it  be  coal,  wood,  oil,  or  gas,  with  the 
oxygen  of  the  air.  Combustion  is  simply  a  process 
of  chemical  combination,  and  the  light  and  heat 
which  are  evolved  in  the  process  are  only  the  con- 
comitants of  the  chemical  change.  Why  those 


LECT.m.]  TESTIMONT  OP   OXYGEN.  83 

v> 

mysterious  influences  of  light  and  heat  are  radi- 
ated from  the  coal  which  is  combining  with  oxygen 
in  our  grates,  we  may  understand  better  hereafter  ; 
but  this  much  we  already  know,  —  that  the  sensa- 
tions of  light  and  heat  are  caused  by  waves  of  an 
ethereal  medium  breaking  upon  the  extremities  of 
the  delicate  nerves  of  our  human  organism ;  and 
that  such  waves  are  set  in  motion  during  the 
chemical  change  which  we  call  combustion.  What 
the  chemist  chiefly  studies,  however,  is  the  change 
itself,  and  to  this  we  will  for  the  present  confine 
our  attention. 

The  products  of  ordinary  combustion,  that  is,  the 
compounds  of  oxygen  with  the  elements  of  coal, 
wood,  and  gas,  are  only  two  in  number,  carbonic- 
acid  gas,  and  aqueous  vapor.  These,  as  is  weU 
known,  are  perfectly  colorless  and  transparent  aeri- 
form substances,  wholly  without  odor  or  taste,  and 
entirely  devoid  of  every  active  quality.  For  this 
reason  they  escape  without  observation  from  the 
burning  wood,  ascend  our  chimneys,  and  by  the 
force  of  diffusion  are  spread  throughout  the  atmos- 
phere ;  but  if,  as  may  readily  be  done  by  chemical 
means,  we  collect  the  neglected  smoke  and  weigh 
it,  we  shall  find  that  it  weighs  much  more  than  the 
burnt  wood,  and,  as  more  careful  experiments  will 
show,  its  weight  is  exactly  equal  to  that  of  the 
wood  added  to  that  of  the  oxygen  of  the  air  con- 
sumed during  the  burning. 

And,  my  friends,  this  smoke,  though  so  long 
unnoticed  by  man,  was  not  overlooked  by  the 


84  RELIGION   AND    CHEMISTRY.  [LECT.  HI. 

Author  of  nature.  It  is  a  part  of  his  grand  and 
beneficent  design  in  the  scheme  of  organic  na- 
ture. No  sooner  do  the  products  of  that  wood 
burning  on  your  hearth  escape  into  the  free  ex- 
panse of  the  outer  air,  than  a  new  cycle  of  changes 
begins.  The  carbonic  acid  and  the  aqueous  vapor, 
after  roving  at  liberty  for  a  time,  are  absorbed 
by  the  leaves  of  some  wide-spreading  tree,  smil- 
ing in  the  sunshine,  and  in  the  tiny  laboratory 
of  their  green  cells  are  worked  up  by  those  won- 
derful agents,  the  sun-rays,  into  new  wood,  ab- 
sorbing from  the  sun  a  fresh  supply  of  power, 
which  is  destined,  perhaps,  to  shed  warmth  and 
light  around  the  fireside  of  a  future  generation. 

But  let  us  not  anticipate  our  subject.  In  a  fu- 
ture Lecture  I  hope  to  discuss  this  wonderful  cycle 
of  changes  at  some  length.  At  present  I  wish  to 
direct  your  attention  to  the  remarkable  contrast 
'of  qualities  presented  by  the  element  oxygen 
in  its  active  and  passive  conditions.  How  is  this 
complete  inversion  of  properties  to  be  explained  ? 
There  is  a  cloud  of  mystery  hanging  over  the  sub- 
ject, which  the  progress  of  knowledge  has  not  as 
yet  entirely  dispelled ;  but  so  far  as  the  cause  is 
known,  I  will  endeavor  to  make  it  intelligible.  The 
difference  in  the  action  of  oxygen  in  these  two  con- 
ditions depends  on  temperature.  At  the  ordinary 
temperature  of  the  air  its  chemical  affinities  are 
dormant,  and,  although  endowed  with  forces  which 
are  irresistible  when  in  action,  it  awaits  the  neces- 
sary conditions  to  call  them  forth.  One  of  the 


.]  TESTIMONY   OF   OXYGEN.  85 

grandest  works  of  ancient  art  which  have  come 
down  to  us  is  the  colossal  statue  of  the  Farnese 
Hercules.  The  hero  of  ancient  mythology  is  repre- 
sented in  an  erect  form,  leaning  on  his  club,  and 
ready  for  action ;  but  at  the  moment  every  one  of 
the  well-developed  muscles  of  his  ponderous  frame 
is  fully  relaxed,  and  the  figure  is  a  perfect  ideal 
of  repose,  yet  a  wonderful  embodiment  of  power. 
Here  in  this  antique  we  have  most  perfectly  typi- 
fied the  passive  condition  of  oxygen,  the  hero  of 
the  chemical  elements.  Raise  now  the  temperature 
to  a  red  heat,  and  in  a  moment  all  is  changed. 
The  dormant  energies  of  its  mighty  powers  are 
aroused,  and  it  rushes  into  combination  with  all 
combustible  matter,  surrounded  by  those  glorious 
manifestations  of  light  and  heat  which  every  con- 
flagration presents. 

In  order  to  evoke  the  latent  forces  in  the  oxy- 
gen of  the  atmosphere,  it  is  not  necessary,  how- 
ever, to  raise  the  temperature  of  any  con-  Fire,  how 
siderable  portion  either  of  the  gas  or  of  sustained- 
the  combustible.  There  is  a  provision  in  nature 
by  which  chemical  combination,  once  started  at 
any  portion  of  the  combustible  mass,  is  sustained 
until  the  whole  is  consumed.  All  chemical  com- 
bination is  attended  by  the  evolution  of  heat,  and 
in  the  combination  of  oxygen  with  most  combusti- 
ble substances  the  amount  of  heat  thus  generated 
is  so  great,  that  by  the  burning  of  one  portion  suf- 
ficient heat  is  evolved  to  raise  the  temperature  of  a 
second  portion  to  the  point  of  ignition,  and  thus 


86  RELIGION   AND    CHEMISTRY.  [LECT.  IH. 

the  process  is  continued.  Consider,  for  example, 
what  takes  place  in  the  burning  of  a  jet  of  gas. 
We  start  the  combustion  by  bringing  the  flame  of  a 
lighted  match  over  the  orifice.  By  this  the  temper- 
ature of  the  gas  and  that  of  the  air  surrounding  it 
are  raised  to  a  red-heat,  and  chemical  combination 
at  once  ensues.  But  the  chemical  union,  as  just 
stated,  is  attended  with  the  evolution  of  great  heat, 
which,  before  it  is  dissipated  by  the  air,  raises  to 
the  point  of  ignition  the  temperature  of  the  next 
portion  of  gas  issuing  from  the  burner.  This,  com- 
bining in  its  turn  with  the  oxygen  of  the  air,  gener- 
ates a  fresh  quantity  of  heat,  and  thus  keeps  up  the 
combustion  so  long  as  the  gas  is  supplied.  What 
I  have  shown  to  be  true  of  these  gas-burners  is 
equally  true  of  all  ordinary  combustion,  and  so  a 
single  spark  may  be  sufficient  to  light  up  a  confla- 
gration which  will  reduce  to  ashes  a  whole  village 
or  involve  a  city  in  ruin. 

Thus  it  appears  that  burning  is  chemical  combi- 
nation with  oxygen,  that  this  union  is  attended 
with  the  evolution  of  heat,  and  that  a  high  temper- 
ature is  the  condition  under  which  oxygen  mani- 
fests its  latent  power.  But  you  may  say,  these 
facts  do  not  explain  the  difference  between  the  two 
states  of  oxygen,  they  merely  give  the  conditions 
under  which  these  states  are  manifested ;  and  this 
is  true.  Why  it  is  that  at  one  temperature  oxy- 
gen is  so  completely  passive,  and  at  another  tem- 
perature, a  few  hundred  degrees  higher,  so  highly 
active,  we  not  only  cannot  explain,  but  we  cannot 


LECT.  III.J  TESTIMONY    OP   OXYGEN.  87 

even  conjecture.     The  facts   are  undisputed ;  the 
causes  lie  hid  among  the  counsels  of  the  All- Wise. 

The  temperature  at  which  oxygen  assumes  its 
active  condition  is  called  the  point  of  ignition.  Al- 
though fixed  for  each  substance,  it  differs  Point  of  }gni. 
very  greatly  with  the  different  kinds  of  tion* 
combustible  matter,  being  determined,  apparently, 
by  their  relative  affinities  for  the  great  fire  element. 
Thus  phosphorus  ignites  at  a  temperature  less  than 
that  of  boiling  water,  sulphur  at  500°,  wood  only 
at  a  full  red  heat,  anthracite  coal  at  a  white  heat, 
while  iron  requires  the  highest  heat  of  a  black- 
smith's forge.  Beginning  with  a  phosphorus  match, 
which  can  be  ignited  by  friction,  and  using  the  more 
combustible  materials  as  kindlings,  we  can  readily 
attain  in  our  furnaces  the  highest  temperature  re- 
quired, and  thus  the  energies  of  this  powerful  agent 
are  fully  at  the  command  of  man.  But  notice  at 
the  same  time  that  the  point  of  ignition  of  wood, 
coal,  and  common  combustibles,  has  been  placed 
sufficiently  above  the  ordinary  temperature  of  the 
air  to  insure  the  general  safety  of  our  combustible 
dwellings  •  and  when  we  consider  how  liable  they 
are,  even  now,  to  accidents  from  fire,  we  shall  ap- 
preciate the  care  which  has  been  taken  by  our 
Heavenly  Father  to  guard  us  against  this  terrible 
danger. 

But  even  this  precaution  would  have  been  in- 
sufficient to  secure  safety,  were  it  not  that  the  ac- 
tive energies  of  oxygen,  even  when  aroused,  have 
been  most  carefully  tempered  by  extreme  dilution. 


88  RELIGION   AND    CHEMISTRY.  [LECT.  ffl. 

It  would  be  easy  to  show  by  experiment  that  the 
slowness  of  combustion  depends  on  the  fact  that 
in  the  atmosphere  oxygen  is  mixed  with  a  great 
mass  of  an  inert  gas,  and  the  proportions  have  been 
so  adjusted  in  the  scheme  of  creation  as  generally 
to  restrain  the  awakened  energies  of  the  fire-ele- 
ment within  the  narrow  limits  which  man  appoints ; 
but  when,  through  his  misfortune  or  carelessness,  it 
overrides  these  limits,  and,  from  administering  to 
man's  wants,  becomes  the  agent  of  his  destruction, 
we  are  reminded  in  the  awful  conflagration  by  what 
a  delicate  tenure  we  hold  our  earthly  possessions, 
and  how  small  a  change  would  be  sufficient  to  in- 
volve all  organized  matter  in  a  general  conflagra- 
tion. Eemember  now  that  fire  is  one  of  the  most 
valuable  servants  of  mankind ;  that  it  is  the  source 
of  all  artificial  heat  and  light ;  that  in  the  steam- 
engine  it  is  the  apparent  origin  of  that  power  which 
animates  the  commerce  and  the  industry  of  the  civ- 
ilized world ;  that  under  its  influence  iron  becomes 
plastic,  and  the  ores  give  up  their  metallic  treasures ; 
that  it  is,  in  fine,  the  agent  of  all  the  arts,  —  and 
you  cannot  wonder  that  in  a  ruder  age  the  Ko- 
mans  should  have  enthroned  its  presiding  deity  on 
Olympus,  or  the  Persians  worshipped  its  supposed 
essence  as  divinity  itself.  Looking  at  it  again,  in 
the  light  of  modern  science,  as  merely  the  mani- 
festation of  the  latent  power  of  this  bland  and  dif- 
fusive atmosphere,  the  truth  seems  almost  incred- 
ible. To  think  that  this,  the  strongest  of  the  chem- 
ical elements,  which,  although  a  permanent  gas, 


LECT.  in.]  TESTIMONY   OF   OXYGEN.  89 

forms  more  than  one  half  of  the  solid  earth,  and 
is  endowed  with  such  mighty  affinities  that  it  is  re- 
tained securely  in  this  solid  state,  could  have  been 
so  shorn  of  its  energies  as  not  to  singe  the  down  of 
the  gossamer,  and  yet  so  tempered  that  its  powers 
may  be  evoked  at  the  will  of  man  and  made  sub- 
servient to  his  wants !  To  me  the  double  condition 
of  oxygen  is  one  of  the  most  remarkable  phenom- 
ena of  nature.  I  ponder  over  it  again  and  again, 
with  increasing  wonder  and  admiration  at  the  skill 
of  the  infinite  Designer,  who  has  been  able  to  unite 
in  the  same  element  perfect  mildness  and  immeas- 
urable power.  It  seems  as  if  the  millennium  of  the 
Hebrew  prophet  were  prefigured  in  the  atmosphere. 
"  The  wolf  also  shall  dwell  with  the  lamb,  and  the 
a  leopard  shall  lie  down  with  the  kid,  and  the  calf 
"  and  the  young  lion  and  the  fatling  together,  and 
"  a  little  child  shall  lead  them." 

If  I  have  succeeded  in  making  clear  the  relations 
of  this  twofold  character  of  oxygen  to  man  and  his 
works,  I  think  that  you  cannot  fail  to  have  been 
impressed  with  the  evidence  of  design  which  the 
subject  affords.  This  evidence  is  seen  in  the  facts, 
first,  that  the  same  element  is  at  different  tempera- 
tures endowed  with  such  opposite  and  apparently 
incompatible  qualities  ;  secondly,  that  in  each  of  its 
conditions  the  properties  are  so  skilfully  adapted  to 
the  functions  which  it  is  appointed  to  perform; 
thirdly,  that  the  temperature  at  which  it  assumes 
its  active  state  has  been  so  accurately  adjusted 
to  the  thermal  conditions  of  the  globe ;  and  lastly, 


90  RELIGION   AND    CHEMISTRY.  [LECT.  HI. 

that  its  active  energies  have  been  so  carefully 
guarded,  and  placed  to  so  great  a  degree  under 
the  control  of  man.  But  we  have  not  as  yet  half 
exhausted  the  subject.  Here,  as  everywhere  else 
in  nature,  the  argument  is  cumulative ;  the  more 
we  study,  and  the  more  our  knowledge  is  enlarged, 
the  more  it  grows  upon  us ;  and  wherever  we  may 
leave  the  field,  we  always  are  conscious  that  there 
is  a  still  richer  harvest  to  be  reaped  beyond. 

If  the  crust  of  the  globe  is  a  fair  sample  of  the 
whole   mass,   oxygen  was  the  chief  material  em- 
ployed  by  the  Great  Architect   in  con- 

Oxygenthe  . 

chief  world-      structing   our   earth.      Moreover,   world- 
building  was  a  process  of  burning   like 
those  we  have  been  studying,  and  the  foundations 
of  the  earth  were  undoubtedly  laid  in  flames. 

When  we  attempt  to  break  up  the  various  ma- 
terials around  us  into  simpler  parts,  we  soon  reach 
a  class  of  substances  which  cannot  be  further  de- 
composed. Simple  inspection  will  show  that  gran- 
ite rock,  for  example,  is  a  mixture  of  three  min- 
erals, called  feldspar,  mica,  and  quartz.  We  know, 
also,  that  feldspar  consists  of  alumina,  potash,  and 
silica,  that  mica  contains  the  same  materials  in 
different  proportions,  and  that  quartz  is  silica  alone. 
Lastly,  the  chemists  have  discovered  that  alumina 
is  composed  of  aluminum  and  oxygen,  potash  of  po- 
tassium and  oxygen,  and  silica  of  silicon  and  oxygen. 
But  here  we  must  stop ;  for  when  you  ask  us  of 
what  these  last-named  materials  are  made,  we  find 


LECT.III.]  TESTIMONY   OF    OXYGEN.  91 

ourselves  in  the  condition  of  the  old  philosopher, 
who  got  on  very  well  with  his  flat  earth,  sup- 
porting it  on  an  elephant,  and  the  elephant  on  four 
tortoises,  until  he  came  to  seek  a  resting-place  for 
the  tortoises ;  but  then  his  theory  failed.  So  is  it 
with  our  science.  These  undecomposed  materials 
are  the  blocks  on  which  the  whole  is  built ;  and  we 
are  totally  ignorant  of  what  lies  below. 

We  call  all  substances  which  have  never  yet 
been  decomposed,  whatever  may  be  their  nature, 
chemical  elements,  and  of  such  about  sixty-five  are 
now  known.  Setting  apart  oxygen  as  the  sup- 
porter of  combustion,  the  great  mass  of  the  re- 
maining elements  are  combustible  ;  that  is,  under 
certain  conditions  they  combine  rapidly  with  oxy- 
gen, evolving  light  and  heat.  Indeed,  many  of  the 
combustible  substances  with  which  we  are  most 
familiar  are  elements.  Charcoal  is  an  element, 
phosphorus  is  an  element,  sulphur  is  an  element, 
iron  and  all  other  metals  are  elements,  and  out  of 
such  combustible  materials,  together  with  oxygen, 
the  world  is  made,  and  chiefly  out  of  oxygen. 

When  we  burn  charcoal  in  air,  or  pure  oxygen 
gas,  the  burning  is  a  process  of  world-making.  The 
charcoal  combines  with  oxygen,  and  the  result  is 
a  transparent,  colorless  gas,  called  carbonic-acid. 
Many  may  not  have  heard  of  such  a  substance  be- 
fore, but  it  is  always  present  in  the  atmosphere,  at 
least  in  small  quantities,  and  if  we  continue  our 
process  of  world-making  a  little  further,  we  shall 
find  that  it  enters  into  the  composition  of  some  of 
the  most  familiar  rocks  and  minerals. 


92  KELIGION   AND    CHEMISTRY.  [LECT.  HI. 

I  have  at  the  bottom  of  this  closed  glass  tube  a 
small  piece  of  a  yellowish-white  metal,  looking  very 
much  like  a  flattened  shot ;  and  so  it  is,  but  the 
metal  is  not  lead,  although  it  resembles  lead  very 
closely.  Like  lead  it  is  quite  soft,  and  can  be 
easily  beaten  into  leaves  thinner  than  writing- 
paper  ;  but  it  is  very  much  lighter  than  lead,  and 
tarnishes  so  rapidly  in  the  air  that  we  are  obliged 
to  keep  it  thus  protected.  We  call  the  metal 
calcium,  and  although  you  may  never  have  seen 
the  substance  before,  it  is  one  of  the  most  abun- 
dant metals  in  nature ;  yet  a  great  rarity,  because 
of  the  extreme  difficulty  with  which  it  is  extracted 
from  its  ores.  When  heated  to  redness,  calcium 
burns  with  a  brilliant  white  light  and  a  scintil- 
lating flame.  In  burning,  it  combines  of  course 
with  oxygen,  and  the  result  is  lime,  common 
quicklime,  such  as  is  used  for  making  mortar. 
This  is  a  process  which  in  the  original  world- 
making  must  have  played  a  very  important  part, 
for  lime  rocks  form  a  large  portion  of  the  earth's 
crust.  None  of  these  rocks,  however,  will  slake  like 
quicklime,  and  we  must  go  a  step  further  in  our 
world-building,  and  bring  in  the  agency  of  water, 
before  we  can  reach  the  actual  condition  of  things. 

We  have  now  before  us  two  products  of  burning, 
one  a  solid,  called  lime,  made  by  uniting  calcium 
with  oxygen,  the  other  a  gas,  called  carbonic-acid, 
made  by  uniting  charcoal  with  oxygen.  Both 
are  soluble  to  a  certain  extent  in  water,  and 
these  clear  solutions,  called  lime-water  and  soda- 


LECT.IH.]  TESTIMONY    OF   OXYGEN.  93 

water  respectively,  are  even  more  familiar  to  you 
than  the  substances  themselves.  Mix  now  the 
solutions  together.  The  water  becomes  at  once 
very  turbid,  and  there  soon  settles  from  it  a  white 
powder.  The  lime  and  carbonic  acid  have  united, 
and  this  is  the  result.  If  we  collect  and  examine 
the  white  powder  we  shall  find  that  it  is  chalk, 
and  from  the  same  material,  spread  in  thick  layers 
over  the  ocean-bed,  and  subsequently  hardened  by 
the  mutual  action  of  heat  and  water,  have  been 
formed  limestone,  marble,  and  the  different  varie- 
ties of  lime  rock,  which  are  all  ores  of  calcium. 

But  we  may  study  with  profit  a  second  ex- 
ample of  world-building.  I  have  here  a  small 
quantity  of  another  very  abundant  element,  called 
silicon,  but,  like  calcium,  a  comparative  rarity,  be- 
cause it  is  with  difficulty  obtained  pure.  It  re- 
sembles in  many  respects  carbon,  and  has  been 
observed  in  three  different  states,  corresponding 
to  charcoal,  graphite,  and  diamond.  Like  carbon, 
it  also  is  combustible,  combining  with  the  oxy- 
gen of  the  air  when  heated  to  a  high  tempera- 
ture, and  forming  a  very  hard  white  solid,  called 
by  chemists  silica,  which  is  the  same  thing  as 
quartz,  rock-crystal,  agate,  jasper,  calcedony,  opal, 
&c.  All  these  familiar  minerals  are  merely  differ- 
ent conditions  of  this  one  material,  and  contain 
over  one  half  their  weight  of  oxygen  gas.  When 
ground  to  a  coarse  powder  by  the  action  of  running 
streams,  they  become  sand,  and  the  grains  of  sand, 
compacted  together,  form  sandstone  and  similar 


94  RELIGION   AND    CHEMISTRY.  [LECT.  HI. 

rocks ;  and  you  will  begin  to  appreciate  the  enor- 
mous amount  of  silicon  which  must  have  been 
burnt  up  in  the  process  of  world-making,  when  you 
learn  that  at  least  one  half  of  the  solid  crust  of 
the  earth  consists  of  silica  in  its  different  varieties. 

Setting  aside  the  silica  for  a  moment,  let  us  turn 
to  another  very  widely  distributed  element,  called 
aluminum.  This  brilliant  white  metal,  comparing 
favorably  even  with  silver  in  lustre,  was  until  very 
recently  as  great  a  rarity  as  calcium  or  silicon ;  but 
within  a  few  years  a  process  has  been  invented  by 
which  it  can  be  extracted  from  its  ore  at  a  cost 
sufficiently  low  to  render  the  metal  available  in 
the  arts,  and  it  has  now  come  into  quite  general 
use  for  making  mathematical  instruments,  for  jew- 
elry, and  for  similar  purposes.  It  forms  also,  with 
copper,  a  valuable  alloy,  which  does  not  readily 
tarnish,  and  resembles  gold  so  closely  that  the 
two  cannot  be  distinguished  by  their  external  ap- 
pearance. 

Aluminum,  like  most  of  the  metals,  is  combusti- 
ble, although  it  does  not  burn  readily  in  the  air, 
unless  the  temperature  is  very  high  and  the  metal 
finely  subdivided ;  but  it  then  burns  very  bril- 
liantly, emitting  a  vivid  light,  and  forming  a  com- 
pound called  by  chemists  alumina,  which  is  melted 
by  the  intense  heat  to  a  yellowish  transparent 
glass,  and  is  the  same  substance  from  which  na- 
ture makes  the  sapphire  and  the  ruby.  Emery 
also,  which,  on  account  of  its  great  hardness,  is 
used  so  largely  for  polishing,  is  only  a  rougher 


LECT.IIL]  TESTIMONY   OF   OXYGEN.  95 

form  of  the  same  material.  Unite  now  the  alumina 
to  silica,  and  we  get  clay.  Burn  the  clay,  and  we 
have,  according  to  the  fineness  ,of  the  materials, 
porcelain,  pottery-ware,  or  bricks. 

Taking  next  the  element  magnesium,  which  is 
also  a  brilliant  white  metal,  allied  to  zinc,  you  notice 
that  it  takes  fire  even  in  the  flame  of  a  candle,  and 
burns  with  dazzling  brilliancy.  The  result  is  mag- 
nesia, so  much  used  as  a  medicine.  Unite  magnesia 
to  silica,  and  we  have,  according  to  the  proportions, 
hornblende  or  augite,  two  minerals  which  abound 
in  many  varieties  of  rock.  Add  water  to  the  com- 
position, and  we  get  also  serpentine  or  soapstone, 
with  several  other  allied  mineral  species. 

I  might  multiply  these  illustrations  indefinitely, 
but  I  will  limit  myself  to  only  one  other  example. 
Here  is  a  metallic  element  called  potassium,  so  light 
and  combustible  that  it  swims  and  burns  on  water. 
Burning  in  water  may  seem,  at  first  sight,  very  par- 
adoxical ;  but  in  studying  chemistry,  we  must  be 
ready  to  give  up  old  prejudices.  Water  is  almost 
pure  oxygen,  containing  in  the  same  volume  more 
than  one  hundred  times  as  much  of  the  fire-element 
as  air,  and  all  combustibles  would  burn  in  water 
were  it  not  that  the  oxygen  is  imprisoned  in  the 
liquid  by  an  immensely  strong  force.  Potassium, 
however,  has  such  intense  chemical  affinities  that 
it  will  break  through  all  bars  and  bolts  in  order  to 
unite  with  oxygen,  and  it  therefore  burns  thus  bril- 
liantly even  in  the  midst  of  water.  The  result  is 
a  white  solid  called  potash,  which  in  the  experi- 


96 


RELIGION   AND    CHEMISTRY. 


[LECT.  HI. 


ment  dissolves  in  the  liquid.  Melt  together  now 
potash,  lime,  and  silicious  sand,  and  we  have  glass. 
Unite  silica,  alumina,  and  potash,  and  we  get  feld- 
spar; combine  them  in  little  different  proportions, 
and  we  have  mica ;  varying  again  the  proportions, 
we  obtain  garnet.  Lastly,  mix  quartz  and  feldspar 
together  with  mica  or  hornblende,  in  an  indiscrimi- 
nate jumble,  and  we  have  the  several  varieties  of 
granitic  rocks. 

Such  then  are  some  of  the  steps  in  the  process 
of  world-building.  I  do  not  mean  to  imply  that 
we  can  reproduce  all  these  substances  in  our  labo- 
ratories, although  even  this  is  true  in  almost  every 
case.  My  object  is  only  to  show  what  must  have 
been  in  general  the  process  of  nature,  and  to  make 
evident  the  fact  that  oxygen  has  been  the  chief 
world-builder.  But  why  call  oxygen  the  world- 
builder  more  than  the  other  elements  ?  This  dia- 
gram will  answer,  and  it  illustrates  one  of  the  most 


Silicon. 

i 

Oxygen. 
i 

Aluminum. 

Magnesium. 
Calcium. 

K  .  Na  Fe  C. 

SHC1N.  |  52  others. 

remarkable  facts  to  which  the  study  of  this  func- 
tion of  oxygen  has  led.     Of  the   65  known   ele- 


LECT.HI.]  TESTIMONY  OP   OXYGEN.  97 


ments,  thirteen  alone  make  up  at  least  y9^  of  the 
whole  known  mass  of  the  earth.  Of  this,  oxygen 
forms  about  |-,  silicon  about  |  ;  then  we  have  alumi- 
num, magnesium,  calcium,  potassium  (K),  sodium 
(Na),  iron  (Fe),  carbon  (C),  sulphur  (S),  hydrogen 
(H),  chlorine  (Cl),  and  nitrogen  (N)  filling  up  nearly 
the  other  fourth,  while  the  52  remaining  elements 
—  including  all  the  useful  metals  except  iron  —  do 
not  constitute  altogether  more  than  T^¥.  The  dia- 
gram, however,  only  represents  the  relative  propor- 
tions very  rudely,  as  the  subdivisions  are  necessarily 
based  on  very  rough  estimates  and  imperfect  data. 

Evidently,  then,  so  far  as  our  knowledge  ex- 
tends, oxygen,  silicon,  and  carbon,  together  with  a 
few  metals,  have  been  the  chief  building-materials 
employed  by  the  Great  Architect,  and  oxygen  has 
been,  as  it  were,  the  universal  cement  by  which  the 
other  elements  have  been  joined  together  to  form 
that  grand  and  diversified  whole  we  call  our  earth. 

One  more  remark  in  regard  to  this  subject,  and 
I  will  close  my  Lecture.  It  is  probable  that  there 
was  a  time,  long  before  even  geological  history, 
when  the  elements  were  in  a  free  state  ;  when  the 
oxygen  now  solidified  was  a  gas  forming  an  atmos- 
phere, and  when  at  the  fiat  of  the  Almighty  the 
union  of  the  elements  began.  Then  our  earth  be- 
came a  bright,  burning  star,  radiating  its  heat  and 
light  into  space.  Indeed,  if  we  accept  the  nebular 
hypothesis  of  Laplace,  the  earth  was  formerly  a  part 
of  the  sun,  was  thrown  off  by  the  centrifugal  force 
from  his  burning  mass,  and  like  a  spark  from  a  forge 


98  KELIGION   AND    CHEMISTRY.  [LECT.  1H, 

soon  burnt  out,  although  after  this  lapse  of  time 
the  great  central  fire  is  burning  still.  But  whether 
Laplace  is  right  or  not,  this  much  is  certain.  The 
crust  of  the  earth,  so  far  as  we  can  examine  it,  is 
like  a  burnt  cinder,  and  the  atmosphere  of  oxy- 
gen which  surrounds  it  is  merely  the  residuum  left 
after  the  general  conflagration,  —  left  because  there 
was  nothing  more  to  burn.  Unmeasured  ages  have 
passed  away  since  then ;  the  earth's  crust  has  cooled 
and  solidified ;  the  waters  have  been  condensed  and 
gathered  into  the  great  ocean-basins ;  the  dry  land 
has  been  covered  with  verdure  and  peopled  with 
all  kinds  of  four-footed  beasts,  winged  fowls,  and 
creeping  things ;  the  waters  have  been  tenanted 
with  countless  forms  of  swimming  creatures;  and, 
last  of  all,  man  has  come  to  live  in  this  fair  crea- 
tion, and  study  the  wonders  of  his  dwelling-place. 
He  finds  on  the  earth's  burnt  crust  an  abundant 
supply  of  combustible  material  for  all  his  wants. 
But  if  the  world  was  once  burnt  up  and  the  ele- 
ments glowed  with  fervent  heat,  how  is  it  that 
these  combustibles  have  been  left  unconsumed  ? 
Modern  science  has  been  able  to  answer  this  ques- 
tion. It  has  discovered  that  during  the  long  geo- 
logical ages  a  silent  power  has  been  slowly  recov- 
ering a  small  amount  of  combustible  material  from 
the  wreck  of  the  first  conflagration.  The  sunbeam 
has  partly  undone  the  work  of  the  fire,  and  what- 
ever now  exists  on  the  earth  unburnt,  wood,  coal, 
or  metal,  we  owe  to  that  wonderful  agent,  the 
solar  light.  How  the  result  has  been  accomplished, 
I  propose  to  consider  in  a  future  Lecture. 


LECTUEE    IV. 

TESTIMONY   OF   OXYGEN. Concluded. 

BESIDES  the  two  extreme  conditions  of  oxygen, 
there  exists  still  a  third,  in  a  measure  intermediate 
between  them,  but  still  differing  essen-  Third  condition 
tially  from  either, — a  condition  in  which  ofoxygen- 
the  element  discharges  functions,  less  brilliant  it  is 
true,  but  not  less  interesting  and  instructive,  than 
those  which  we  studied  in  the  last  Lecture.  The 
phenomena  in  which  this  condition  of  oxygen  is 
chiefly  active  require,  as  a  general  rule,  months, 
or  even  years,  for  their  full  manifestation.  More- 
over, they  are  so  silent  and  unobtrusive,  as  fre- 
quently to  be  passed  unnoticed ;  but  neverthe- 
less, when  we  have  become  acquainted  with  their 
magnitude  and  importance,  I  am  sure  you  will 
agree  with  me  that  they  far  surpass  in  true 
grandeur  those  dazzling  displays  of  power  which 
the  fire-element  manifests  when  fully  aroused. 
This  third  phase  of  the  element  can  bet  best 
studied  in  its  effects,  and  to  two  of  these  I  will 
now  ask  your  attention. 

Every  one  knows  that,  when  wood  or  any  other 
organized  structure  is  exposed  to  the  moist  atmos- 
phere, it  gradually  decays.    It  first  be-      Decay 
comes  rotten,  and  then  slowly  disappears. 


100  RELIGION   AND    CHEMISTRY.  [LEOT.  IV. 

All  may  not  know,  however,  that  decay  consists  in 
a  slow  union  of  the  organized  structure  with  oxy- 
gen, and  that  the  log  of  wood  which  is  left  to  rot 
in  the  forest  undergoes  precisely  the  same  change 
as  one  which  is  burnt  on  the  hearth.  The  sole 
difference  is,  that,  while  the  last  is  burned  up  in  a 
few  hours,  the  first  entirely  disappears  only  after 
the  lapse  of  many  years.  Wood,  like  all  organized 
vegetable  structures,  consists  mainly  of  three  ele- 
ments, charcoal,  hydrogen,  and  oxygen.  When 
heated  on  the  hearth,  in  contact  with  the  air,  it 
takes  fire  and  burns  \  that  is,  its  combustible  ele- 
ments combine  with  oxygen,  the  carbon  to  form 
carbonic  acid,  and  the  hydrogen  to  form  aqueous 
vapor,  both  of  which  escape  by  the  chimney.  But 
of  these  two  ingredients  of  the  wood,  hydrogen  is 
by  far  the  most  combustible ;  that  is,  it  has  the 
greatest  tendency  to  combine  with  oxygen,  and 
therefore  burns  first,  leaving  the  less  combustible 
charcoal  in  the  form  of  glowing  coals.  If  at  this 
point  we  take  up  one  of  these  coals  and  quench  it 
in  water,  it  will  be  found  to  be  common  black  char- 
coal ;  but  if  left  on  the  hearth,  the  coal  also  burns, 
gradually  smouldering  away,  and  passing  up  the 
chimney  as  carbonic-acid  gas. 

Quite  a  similar  succession  of  phenomena  is  pre- 
sented in  the  forest  during  the  process  of  decay. 
In  decay,  as  in  burning,  the  oxygen  of  the  air 
unites  with  the  hydrogen  of  the  wood  more  rapid- 
ly than  with  the  charcoal,  and  in  consequence  the 
rotten  wood  becomes  darker  and  darker,  from  the 


LECT.IV.]  TESTIMONY   OP   OXYGEN.  101 

excess  of  black  charcoal,  as  the  change  advances. 
Moreover,  if  the  supply  of  air  is  insufficient,  as 
when  the  wood  is  buried  in  swamps,  it  is  finally 
reduced  to  coal,  which  corresponds  to  half-burnt 
wood.  In  the  open  air,  however,  the  charcoal  as 
well  as  the  hydrogen  is  burnt,  and  the  log  of  wood 
is  resolved,  as  in  ordinary  combustion,  into  carbonic 
acid  and  water,  leaving  only  a  few  handfuls  of 
earth  to  mark  the  spot  where  it  lay.  This  change 
requires  years  before  it  is  fully  consummated,  and 
it  is  not  therefore  wonderful  that  its  nature  should 
not  have  been  understood  until  a  comparatively 
recent  period.  Thanks  to  modern  chemistry,  the 
subject  is  now  less  obscure.  We  may  not  be  able 
to  trace  all  the  steps  of  the  process,  but  this  much 
we  know.  Decay  and  burning  are  essentially  the 
same  chemical  change.  The  substances  involved 
are  the  same,  the  results  are  the  same,  and  we  have 
even  been  able  to  prove  that  the  amount  of  heat 
generated  is  the  same,  the  only  difference  being, 
that,  in  burning,  the  whole  amount  of  heat  is  set 
free  in  a  few  hours,  producing  phenomena  of  in- 
tense ignition ;  while  in  the  process  of  decay  the 
same  quantity,  slowly  evolved  during  perhaps  a 
century,  escapes  notice. 

It  has  been  observed,  that,  if  wood  be  left  in 
contact  with  dry  oxygen,  it  may  be  kept  indefi- 
nitely without  undergoing  change,  —  a  fact  suf- 
ficiently proved  by  the  mummy  cases  of  Egypt, 
which  in  that  dry  climate  have  been  preserved  for 
over  three  thousand  years ;  —  also,  that  if  wood  is 


102  RELIGION   AND    CHEMISTRY.  [LECT.  IV. 

impregnated  with  many  salts,  as  in  the  process  of 
Kyanizing  or  Burnetizing,  decay  may  be  arrested 
even  in  a  damp  situation  for  a  long  time.  In  both 
cases  the  prevention  depends  on  destroying  cer- 
tain very  unstable  compounds  which  are  present 
in  all  green  wood,  and  which  start  the  decay. 
These  are  termed  by  chemists  albuminous  sub- 
stances, the  chief  of  which,  vegetable  albumen,  is 
almost  identical  with  the  white  of  an  egg.  The 
great  bulk  of  all  vegetable  structures,  as  was  stated 
above,  consists  of  only  three  elements,  charcoal, 
hydrogen,  and  oxygen ;  but  these  albuminous  sub- 
stances —  which,  as  a  rule,  are  present  only  in  very 
small  quantities  —  contain  in  addition  to  the  three 
just  mentioned  a  fourth  element,  nitrogen.  Partly 
because  they  contain  nitrogen,  and  partly,  unques- 
tionably, in  consequence  of  the  complex  manner  in 
which  the  four  elements  are  combined,  the  albumi- 
nous substances  are  vastly  more  unstable  than  the 
great  mass  of  vegetable  matter,  and  in  the  pres- 
ence of  moisture  they  soon  undergo  an  internal 
change,  called  putrefaction,  or  fermentation,  by 
which  they  are  broken  up  into  simpler  compounds. 
The  precise  nature  of  the  process  is  not  understood, 
but  nothing  appears  to  be  added  to  the  substance 
unless  it  be  water,  and  the  change  seems  to  consist 
in  the  falling  to  pieces  of  a  complex  organic  struc- 
ture. At  all  events,  oxygen  gas  is  piot  essential 
to  the  process,  but  the  oxygen  of  the  air  which 
happens  to  be  in  contact  with  the  fermenting 
substances  in  some  mysterious  way  undergoes  a 


LECT.IV.]  TESTIMONY   OF   OXYGEN.  103 

remarkable  change.  It  becomes  endowed  with  ac- 
tive properties  even  at  the  ordinary  temperature, 
and,  with  its  affinities  thus  exalted,  slowly  con- 
sumes the  wood,  together  with  all  other  organic 
compounds  present.  Moreover,  the  process,  once 
started,  sustains  itself.  As,  in  burning,  the  union 
of  the  combustible  matter  with  oxygen  engenders 
sufficient  heat  to  maintain  the  surrounding  gas  in 
its  highly  active  modification,  so  in  like  manner 
the  process  of  decay  seems  to  modify  continually 
the  neighboring  oxygen,  arousing  its  energies,  and 
thus  continuing  the  change  when  once  begun. 

While  the  plant  is  in  great  measure  made  up 
of  non-nitrogenized  substances,  the  animal,  on  the 
other  hand,  consists  almost  entirely  of  albuminous 
compounds.  The  flesh,  the  nerves,  and  the  bones 
of  our  bodies  all  contain  nitrogen,  and,  like  the 
vegetable  albumen,  are  prone  to  decay ;  and  this 
change  is  constantly  going  on  in  our  living  mem- 
bers. In  a  most  profound  sense,  "  in  the  midst  of 
life  we  are  in  death."  The  materials  of  our  bodies 
are  being  constantly  renewed,  and  the  great  mass 
of  their  structure  changes  in  less  than  a  year.* 
At  every  motion  of  your  arm,  and  at  every  breath 
you  draw,  a  portion  of  the  muscles  concerned  is 
actually  burnt  up  in  the  effort.  During  life,  in 

*  The  rapidity  of  the  change  has  not  been  accurately  determined. 
Some  authors  state  that  the  great  mass  of  the  body  changes  every 
month,  and  when  we  consider  the  large  quantities  of  water,  carbonic 
acid,  and  ammonia  daily  secreted,  the  statement  appears  credible ;  but 
in  the  absence  of  direct  proof  we  have  set  the  limit  unnecessarily  high 
in  order  to  avoid  the  slightest  exaggeration. 


104  RELIGION  AND    CHEMISTRY.  [LECT.  IV. 

some  utterly  mysterious  manner,  beyond  the  range 
of  all  human  science,  the  various  gases  and  vapors 
of  the  atmosphere,  together  with  a  small  amount 
of  a  few  earthy  salts,  are  elaborated  into  vari- 
ous organized  structures.  They  first  pass  into  the 
organism  of  the  plant,  and  thence  are  transferred 
to  the  body  of  the  animal  •  but  no  sooner  are 
they  firmly  built  into  the  animal  tissues,  than  a 
destructive  change  begins,  by  which  before  long 
they  are  restored  to  the  air  or  the  soil,  only  to 
renew  the  same  cycle  of  ceaseless  change.  Life, 
during  its  whole  existence,  is  an  untiring  builder, 
the  oxygen  of  the  atmosphere  a  fell  destroyer ; 
and  when  at  last  the  builders  cease,  then  the  spirit 
takes  its  heavenward  flight,  and  leaves  the  frail 
tenement  to  its  appointed  end.  Dust  returns  to 
the  dust,  and  these  mortal  mists  and  vapors  to 
the  air. 

I  know  that  there  are  some  who  entertain  a 
vague  fear  that  these  wrell-established  facts  of 
Doctrine  of  the  chemistry  conflict  with  one  of  the  most 
resurrection,  cherished  doctrines  of  the  Christian  faith ; 
but  so  far  from  this,  I  find  that  they  elucidate  and 
confirm  it.  I  admit  that  they  do  disprove  that 
interpretation  frequently  given  to  the  doctrine  of 
the  resurrection,  which  assumes  that  these  same 
material  atoms  will  form  parts  of  our  celestial 
bodies ;  but  then  I  find  that  this  interpretation  is 
as  much  opposed  to  Scripture  as  to  science.  The 
Saviour  himself,  in  his  reply  to  the  incredulous 
Sadducees,  severely  rebuked  such  a  material  con- 


LECT.IV.]  TESTIMONY   OF   OXYGEN.  105 

ception  of  his  spiritual  revelation,  and  the  great 
Apostle  to  the  Gentiles,  in  his  vision  of  the  glori- 
fied body,  distinctly  declares  that  this  body  is  not 
the  body  that  shall  be ;  but  that,  as  the  grain 
sown  in  the  furrow  rises  into  the  glory  of  the  full- 
eared  corn,  "so  when  this  corruptible  shall  have 
put  on  incorruption,  and  this  mortal  shall  have 
put  on  immortality,"  our  natural  body,  sown  in 
dishonor  and  weakness,  will  be  raised  a  spiritual 
body,  clothed  in  glory  and  in  power.  "And  as 
"  we  have  borne  the  image  of  the  earthy,  we  shall 
"  also  bear  the  image  of  the  heavenly." 

The  glorious  doctrine  of  the  resurrection  here 
presented,  modern  scientific  discoveries  most  fully 
confirm.  They  have  shown  that  our  only  abiding 
substance  is  merely  the  passing  shadow  of  our  out- 
ward form,  that  these  bones  and  muscles  are  dying 
within  us  every  day,  that  our  whole  life  is  an  un- 
ceasing metempsychosis,  and  that  the  final  death  is 
but  one  phase  of  the  perpetual  change.  Thus  the 
idea  of  a  spiritual  body  becomes  not  only  a  possible 
conception,  but,  more  than  this,  it  harmonizes  with 
the  whole  order  of  nature ;  and  now  that  we  can 
better  trace  the  processes  of  growth  in  the  organic 
world,  and  understand  more  of  their  hidden  se- 
crets, the  inspired  words  of  Paul  have  acquired 
fresh  power,  and  convey  to  us  a  deeper  meaning 
than  they  ever  gave  to  the  early  Fathers  of  the 
Church.  It  is  no  wonder  that,  when  men  were  less 
enlightened,  the  doctrine  should  have  been  misin- 
terpreted ;  but  now,  when  the  truth  has  been  illu- 

5* 


106  RELIGION   AND    CHEMISTRY.  [LECT.  IV. 

minated  by  the  study  of  nature,  why  longer  harass 
the  understanding  and  vex  the  spirit  with  these 
material  clogs  ?  Hear  again  the  words  of  the 
Apostle :  "This  I  say,  brethren,  that  flesh  and  blood 
cannot  inherit  the  kingdom  of  God ;  neither  doth 
corruption  inherit  incorruption."  "For  this  cor- 
ruptible must  put  on  incorruption,  and  this  mortal 
must  put  on  immortality."  And  now,  turning  to 
the  glorious  truth  as  Christ  revealed  it  and  Paul 
preached  it,  how  greatly  is  our  faith  strength- 
ened by  these  lights  of  nature !  All  philosophy 
assures  us  that  the  finite  and  limited  can  be  mani- 
fested only  under  form. 

"  That  each,  who  seems  a  separate  whole, 
Should  move  his  rounds,  and,  fusing  all 
The  skirts  of  self  again,  should  fall 
Eemerging  in  the  general  Soul, 

"  Is  faith  as  vague  as  all  unsweet : 
Eternal  form  shall  still  divide 
The  eternal  soul  from  all  beside  ; 
And  I  shall  know  him  when  we  meet." 

Chemistry  has  shown  us  that  it  is  the  form  alone 
of  our  mortal  bodies  which  is  permanent,  and  that 
we  retain  our  personality  under  constant  change ; 
and  lastly,  in  organic  nature,  the  sprouting  of  the 
seed,  the  breaking  of  the  bird  from  the  egg,  the 
bursting  of  the  butterfly  from  the  chrysalis,  and 
ten  thousand  other  transmutations  not  less  won- 
derful, which  we  are  daily  witnessing  around  us, 
all  unite  their  analogy  to  elucidate  and  confirm 
the  glorious  and  comforting  doctrine  of  a  material 
resurrection  in  form. 


LECT.IV.]  TESTIMONY   OF   OXYGEN.  107 

Moreover,  when  we  remember  that  our  organs 
of  vision  and  hearing  are  capable  of  receiving  im- 
pressions either  of  light  or  sound  only  when  the 
rapidity  of  the  undulations  which  cause  them  is 
comprised  within  certain  very  narrow  limits,  and 
when  we  recall  the  facts  stated  in  a  previous 
Lecture,  that  there  are  waves  of  light  and  sound 
of  which  our  dull  senses  take  no  cognizance,  that 
there  is  a  great  difference  even  in  human  per- 
ceptivity, and  that  some  men,  more  gifted  than 
others,  can  see  colors  or  hear  sounds  which  are 
invisible  or  inaudible  to  the  great  bulk  of  mankind, 
you  will  appreciate  how  possible  it  is  that  there 
may  be  a  world  of  spiritual  existence  around  us  — 
inhabiting  this  same  globe,  enjoying  this  same  na- 
ture —  of  which  we  have  no  perception ;  that  in 
fact  the  wonders  of  the  New  Jerusalem  may  be  in 
our  midst,  and  the  songs  of  the  angelic  hosts  filling 
the  air  with  their  celestial  harmony,  although  un- 
heard and  unseen  by  us.  Let  me  not  be  under- 
stood as  implying  that  science  has  in  any  sense 
revealed  to  us  a  spiritual  world,  or  that  it  gives 
the  slightest  shadow  of  support  to  those  products 
of  imposture,  credulity,  and  superstition,  which, 
under  the  name  of  witchcraft,  mesmerism,  or  spirit- 
ualism, have  in  every  age  of  the  world  deceived 
so  many.  The  only  revelation  man  has  received 
of  a  spiritual  existence  is  contained  in  the  Bible ; 
but  modern  science  has  rendered  the  conception 
of  such  an  existence  possible,  and  in  this  way  has 
removed  a  source  of  doubt.  The  materialist  can  no 


108  RELIGION   AND    CHEMISTRY.  [LECT.  IV. 

longer  say  that  the  spiritual  world  is  inconceivable  ; 
for  these  discoveries  show  that  it  may  be  included 
in  the  very  scheme  of  nature  in  which  we  live, 
and  thus,  although  science  may  not  remove  the 
veil,  it  at  least  answers  this  cavil  of  materialism. 

Keturning  now  to  the  main  subject,  consider  for 
a  moment  the  importance  of  this  ghostly  office  of 
oxygen  in  the  scheme  of  organic  nature.  Keflect 
how  soon  this  fair  world  would  become  a  great 
charnel-house  were  it  not  for  these  provisions,  by 
which  its  youth  is  constantly  renewed.  Remember 
also  that  this  process  of  decay  furnishes  the  mate- 
rials from  which  young  life  builds  her  fresh  and 
blooming  forms  ;  that,  although  in  the  midst  of  life 
we  are  in  death,  it  is  equally  true  that  death  is 
only  a  phase  of  life.  Then  these  changes  of  out- 
ward nature  will  assume  a  new  aspect.  It  will 
be  seen  that  they  are  the  beneficent  provisions  of 
infinite  wisdom,  in  themselves  full  of  interest  and 
beauty,  and  only  sad  and  melancholy  as  they  are  as- 
sociated with  bereaved  affections  and  disappointed 
hopes,  or  with  that  only  real  death,  the  moral  death 
of  the  soul.  "  0  death,  where  is  thy  sting  ?  0 
"  grave,  where  is  thy  victory  ?  The  sting  of  death 
"  is  sin ;  and  the  strength  of  sin  is  the  law.  But 
"  thanks  be  to  God,  which  giveth  us  the  victory 
"through  our  Lord  Jesus  Christ." 

I  might  profitably  occupy  several  hours  in  de- 
scribing the  various  processes  of  slow  combustion, 
for  they  are  all  rich  in  illustrations  of  skilful  de- 
sign; but  I  must  content  myself  with  only  one 


LECT.  IV.]  TESTIMONY    OF    OXYGEN.  109 

other  example,  and  from  the  many  which  crowd 
upon  ine  I   have  chosen  respiration,  be- 

Respiration. 

cause  it  is  so  well  understood  and  be- 
cause it  is  so  intimately  associated  with  our  own 
physical  existence.  Kespiration  is  a  true  example 
of  combustion.  The  seat  of  the  combustion  is 
the  lungs.  The  substance  burnt  is  sugar.  The 
products  are  carbonic-acid  gas  and  water. 

The  materials  of  animal  food  may  be  divided  in- 
to three  classes :  non-nitrogenized  substances,  such 
as  starch  and  sugar ;  nitrogenized  substances,  like 
lean  meat  and  eggs;  and,  lastly,  fatty  substances, 
like  butter.  To  these  must  be  added  a  small  pro- 
portion of  earthy  salts,  which,  however,  as  they 
enter  into  the  composition  of  almost  all  varieties 
of  food,  do  not  properly  form  a  distinct  class.  All 
of  the  three  classes  of  food  are  absolutely  neces- 
sary to  support  the  life  of  the  higher  animals, 
and  especially  of  man,  and  they  are  all  contained 
in  those  articles  of  diet  which  will  of  themselves 
alone  sustain  life.  Milk  may  be  regarded  as  the 
type  of  animal  food. 

Composition  of  Milk.* 

Natural  state,  ^vaporated 

Water,  87 

Curd  or  casein,  4£  34£ 

Butter  or  fat,  3  23f 

Sugar  (of  milk)  4f  37 

Ash  (nearly)  £                       4£ 

100  100 

*  Johnston's  Chemistry  of  Common  Life. 


110  RELIGION   AND    CHEMISTRY.  [!ECT.  IV. 

It  contains,  in  the  first  place,  a  non-nitrogenized 
substance,  sugar ;  in  the  second  place,  a  nitrogen- 
ized  substance,  casein,  which  separated  from  milk 
forms  cheese ;  and,  lastly,  a  fatty  substance,  which 
when  separated  by  churning  forms  butter. 

"Wlieaten  Bread.         Lean  Beef. 

Water  (and  blood),  45  78 

Fibrin  or  gluten,  6  19 

Fat,  1  3 

Starch,  &c.,  48 

100  100 

Bread,  again,  consists  of  starch,  a  non-nitrogenized 
substance,  of  gluten,  a  nitrogenized  substance,  and 
it  also  contains  about  two  per  cent  of  a  peculiar 
oil.  No  article  of  food  which  does  not  contain 
all  three  of  these  classes  of  substances  can  alone 
support  life  for  any  length  of  time.  A  man 
would  starve  to  death  on  starch  alone,  on  meat 
alone,  or  on  butter  alone.  The  relative  propor- 
tion, however,  in  which  these  three  classes  of 
substances  are  required  by  man,  depends  on  his 
outward  circumstances,  such  as  the  climate,  his 
physical  activity,  his  occupation,  or  his  peculiar 
temperament,  and  to  the  right  balance  of  his  food 
he  is  guided  by  experience. 

The  different  classes  of  food  serve  different  func- 
tions in  the  body.  The  nitrogenized  and  a  portion 
of  the  fatty  substances  are  used  to  supply  the  con- 
stant waste  of  the  tissues  which  result  from  all  the 
animal  processes.  They  are  in  some  unknown  way 


LECT.  IV.J  TESTIMONY   OF   OXYGEN.  Ill 

vitalized  in  the  system,  and  converted  into  new 
muscles,  tendons,  and  nerves,  which  take  the  place 
of  those  that  have  been  used  up.  On  the  other 
hand,  the  non-nitrogenized  substances,  such  as 
starch,  are  supposed  to  take  no  part  in  the  for- 
mation of  new  tissues,  and  to  be  merely  the  fuel 
by  which  the  animal  heat  is  maintained.  Let  us 
very  briefly  follow  these  substances  through  the 
body,  and  see  when  and  how  they  are  burnt. 

By  far  the  greater  part  of  our  daily  food  consists 
of  varieties  of  starch  or  sugar.  These  two  sub- 
stances are  almost  identical  in  composition,  and 
starch  may  be  converted  into  sugar  with  the  great- 
est ease.  Leaving  out  of  view  the  large  amount 
of  water  which  all  our  food  contains,  we  find  that  of 
wheaten  bread  no  less  than  39  per  cent  consists 
of  starch  or  sugar ;  of  potatoes  fully  92  per  cent 
is  made  up  of  the  same  materials,  and  in  general 
they  form  over  four  fifths  of  the  solid  part  of  all 
our  food.  These  substances  when  taken  into  the 
stomach  are  almost  instantaneously  converted  by 
the  saliva  and  the  gastric  juice  into  the  variety 
of  sugar  known  as  grape-sugar,  so  called  because 
it  is  the  sweet  principle  of  ripe  grapes.  The  sweet 
principle  of  honey  and  molasses,  and  the  incrusta- 
tion which  is  so  frequently  seen  on  figs  and  raisins, 
are  also  essentially  the  same  substance.  Grape- 
sugar,  being  very  soluble,  dissolves  in  the  water 
present,  and  the  solution  is  absorbed  by  the  veins 
which  ramify  on  the  surface  of  the  intestinal  ca- 
nal, into  which  the  digested  food  passes  from  the 


112  RELIGION  AND    CHEMISTRY.  [LECT.  IV. 

stomach.  The  blood,  now  containing  sugar  in  so- 
lution, returns  through  the  liver  to  the  right  side 
of  the  heart,  and  by  this  organ,  which  consists  es- 
sentially of  two  ingeniously  contrived  force-pumps, 
arranged  side  by  side,  it  is  forced  through  the 
lungs,  where  the  sugar  is  brought  in  contact  with 
the  air.  Let  us  next  examine  for  a  moment  this 
remarkable  structure. 

The  lungs,  as  is  well  known,  consist  of  two  large 
organs,  on  either  side  of  the  chest,  called  the  left 
and  the  right  lung.  The  right  lung  is  divided  into 
three  smaller  lungs,  called  lobes,  the  left  into  but 
two.  On  examining  any  one  of  these  lobes  it  will 
be  found  to  be  made  up  of  an  immense  number 
of  small  membranous  bags,  all  closely  packed  to- 
gether. These  small  bags,  called  cells,  connect  by 
means  of  the  bronchial  tubes  and  windpipe  with 
the  air,  through  the  nose  and  mouth.  They  vary 
in  size,  but  on  an  average  are  about  T^7  of  an 
inch  in  diameter,  and  the  total  number  of  the 
cells  in  the  lungs  has  been  estimated  at  six  hun- 
dred millions.  Their  walls  are  exceedingly  thin, 
and  the  cells  may  therefore  be  easily  compressed. 
The  whole  mass  of  the  lungs  is  also  exceedingly 
elastic,  and  by  the  action  of  a  system  of  muscles 
their  volume  is  alternately  increased  and  dimin- 
ished in  the  process  of  respiration.  The  amount 
of  air  which  is  thus  drawn  into  the  cells,  and 
again  expelled  at  each  inspiration,  differs  in  dif- 
ferent individuals.  The  average  quantity  in  the 
ordinary  tranquil  respiration  of  an  adult  is  about 


LECT.IV.]  TESTIMONY   OF   OXYGEN.  113 

a  pint ;  but  in  a  full  respiration  it  may  be  as 
much  as  two  and  a  half  pints,  and  by  an  effort 
the  lungs  may  be  made  to  inhale  from  five  to 
seven  pints.  As  the  average  in  health  is  about 
eighteen  inspirations  a  minute,  which  corresponds 
to  about  eighteen  pints  of  air  inhaled  and  ex- 
haled, it  follows  that  three  thousand  gallons  of 
air  pass  through  the  lungs  of  an  adult  man 
every  day.  Some  estimate  it  as  high  as  four 
thousand  gallons  a  day  for  an  average  man  in 
average  circumstances,  and  as  high  as  five  thou- 
sand seven  hundred  gallons  a  day  for  an  athletic 
man  undergoing  severe  exertion.  In  order  that 
you  may  form  an  idea  of  this  quantity,  I  will 
add  that  four  thousand  gallons  of  air  would  fill 
a  room  measuring  about  eight  and  a  half  feet  in 
each  dimension. 

Let  us  now  turn  to  the  blood,  and  examine  the 
apparatus  by  which  it  is  exposed  to  the  air  in 
the  lungs.  As  we  have  already  seen,  the  blood 
charged  with  sugar  is  received  into  the  heart,  from 
whence  it  is  pumped  through  a  long  tube,  called 
the  pulmonary  artery,  into  the  lungs.  This  artery 
divides  again  and  again  until  it  is  reduced  to  very 
small  capillary  tubes,  which  ramify  on  the  surfaces 
of  the  air-cells.  The  walls  of  these  capillaries  are 
formed  of  the  thinnest  conceivable  membrane,  so 
as  to  bring  the  blood  into  as  close  contact  as  pos- 
sible with  the  air.  Here  oxygen  gas  is  absorbed 
in  large  quantities,  and  carbonic-acid  gas  evolved. 
The  blood  now  holds  in  solution  at  the  same  time 


114  EELIGION   AND    CHEMISTRY.  [LECT.  IV. 

oxygen  gas  and  sugar,  and,  thus  charged,  it  returns 
by  a  series  of  veins  to  the  left  side  of  the  heart, 
when  by  the  second  of  the  two  force-pumps  it  is 
again  forced  through  the  general  circulation  of  the 
body.  In  the  mean  time  the  oxygen  absorbed  by 
the  blood  while  in  the  lungs  burns  up  the  sugar. 
Sugar,  like  wood,  consists  of  carbon,  hydrogen,  and 
oxygen.  The  last  two  are  present  in  the  propor- 
tions to  form  water,  so  that  sugar  may  be  said  to 
be  composed  of  charcoal  and  water.  Of  these  two 
substances  the  charcoal  only  is  combustible.  This, 
during  the  circulation  of  the  blood,  is  slowly  burnt 
up  by  the  dissolved  oxygen,  and  converted  into 
carbonic  acid,  which  remains  in  solution  until  it  is 
discharged,  when  the  blood  returns  again  to  the 
lungs,  or  else  escapes  through  the  skin. 

Thus  it  appears  that  respiration  is  a  process  of 
combustion,  in  which  the  fuel  is  sugar,  and  the 
smoke  carbonic  acid  and  aqueous  vapor.  I  need 
not  dwell  on  a  fact  so  universally  known  as  the 
presence  of  carbonic  acid  in  the  breath.  All,  how- 
ever, may  not  know  how  large  is  the  volume  of 
this  gas  which  they  daily  exhale.  It  varies  with 
age,  sex,  food,  health,  and  a  variety  of  other  cir- 
cumstances. In  a  full-grown  man  the  weight  of 
carbonic  acid  evolved  from  the  lungs  varies  from 
one  to  three  pounds  in  twenty-four  hours,  which 
is  equivalent  to  from  nine  to  twenty-seven  cubic 
feet.  During  the  present  Lecture  the  amount  of 
carbonic  acid  which  has  been  exhaled  into  this 
room  by  my  audience  is  equal  to  at  least  seven 


LECT.IV.]  TESTB10NY   OF   OXYGEN.  115 

hundred  and  fifty  cubic  feet,*  and  would  fill  a 
room  measuring  about  nine  feet  in  each  direction. 
From  the  quantity  of  carbonic-acid  gas  exhaled 
we  can  very  readily  calculate  the  amount  of  char- 
coal burnt,  which  in  a  full-grown  man  will  vary 
from  five  to  fifteen  ounces  in  twenty-four  hours. 
Hence,  the  amount  of  charcoal  which  in  the  form 
of  sugar  has  been  burnt  up  in  the  lungs  of  my 
audience  during  the  last  hour,  is  equal  to  at  least 
twenty-six  pounds,*  which  I  have  had  weighed 
out  and  placed  on  the  Lecture  table,  in  order  to 
give  you  an  idea  of  the  quantity.  Moreover,  it 
has  been  proved  that  the  quantity  of  heat  evolved 
by  a  given  amount  of  charcoal  in  burning  is  abso- 
lutely the  same,  whether  the  combustion  be  rapid 
or  slow,  so  that  the  same  amount  of  heat  has  been 
generated  in  our  bodies  during  the  last  hour  by 
the  slow  process  of  respiration  as  would  have  been 
set  free  by  burning  this  basketful  of  charcoal.  It 
is  no  wonder,  then,  that  the  temperature  of  the 
body  is  always  so  much  above  that  of  the  air,  and 
that  even  in  the  coldest  climate  the  heat  of  the 
blood  is  maintained  as  high  as  ninety-six  degrees. 
In  regulating  the  temperature  of  his  body,  man 
follows  instinctively  the  same  rules  of  common 
sense  which  he  applies  in  warming  his  dwellings. 
In  proportion  as  the  climate  is  cold,  he  supplies  the 
loss  of  heat  by  burning  more  fuel  in  his  lungs,  and 
hence  the  statements  of  arctic  voyagers,  who  have 
told  us  that  twelve  pounds  of  tallow-candles  make 

*  Calculated  for  one  thousand  persons. 


116  RELIGION   AND    CHEMISTRY.  [LECT.  IV. 

only  an  average  meal  for  an  Esquimaux,  are  not 
inconsistent  with  the  deductions  of  science. 

Kespiration,  then,  like  decay,  is  a  process  of  slow 
combustion,  in  which  the  oxygen  of  the  air  attacks 
and  consumes,  even  at  the  ordinary  temperature, 
the  sugar  in  the  blood.  Let  us  now  compare  with 
it  the  rapid  combustion  of  the  same  substance. 
During  this  Lecture  every  robust  man  present  has 
on  an  average  burnt  up  the  equivalent  of  about  two 
ounces  of  sugar.  This  combustion  has  taken  place 
so  quietly,  and  has  set  free  the  requisite  amount  of 
heat  so  gradually,  that  we  have  not  been  conscious 
of  it.  In  the  blood,  where  it  has  been  going  on, 
sugar  and  oxygen,  as  we  have  seen,  are  in  close 
contact.  In  this  crucible  I  have  mixed  together 
just  two  ounces  of  sugar  and  two  ounces  and  a 
quarter  of  solidified  oxygen,  solidified  by  the  force 
of  chemical  affinity  and  bound  up  in  a  white  salt 
called  chlorate  of  potash.  The  oxygen  and  sugar 
are  therefore  here  lying  side  by  side,  as  in  the 
blood,  but  the  conditions  of  slow  combustion  which 
exist  in  the  body  not  being  present  in  the  cruci- 
ble, they  will  remain  in  contact  indefinitely,  until 
some  external  agency  is  applied.  The  oxygen  is 
now  in  its  passive  condition,  but  a  single  drop  of 
sulphuric  acid  will  arouse  its  dormant  energies, 
and  you  have  instantly  one  of  the  most  dazzling 
displays  of  combustive  energy  which  can  be  pro- 
duced by  art.  The  only  difference  between  this 
brilliant  deflagratron  and  the  combustion  which, 
during  the  last  hour,  has  taken  place  in  each  of 


LECT.IV.]  TESTIMONY   OP   OXYGEN.  .117 

our  bodies,  is  simply  this ;  the  heat  which  in  the 
blood  has  been  imperceptibly  evolved  during  an 
hour,  was  here  concentrated  into  a  few  moments, 
and  therefore  produced  phenomena  of  intense  igni- 
tion. All  the  other  conditions,  the  material  burnt, 
the  quantity  of  material  employed,  the  products 
generated,  and  the  amount  of  heat  evolved,  are  in 
both  cases  essentially  the  same. 

On  comparing  these  two  phenomena  together, 
reflect  for  a  moment  on  the  false  estimate  which 
we  are  apt  to  make  of  the  phenomena  of  nature. 
The  splendid  displays  of  combustion  arrest  our 
attention  by  their  very  brilliancy,  while  we  over- 
look the  silent  yet  ceaseless  processes  of  respira- 
tion and  decay,  before  which,  in  importance  and 
magnitude,  the  grandest  conflagrations  sink  into  in- 
significance. These  are  but  the  spasmodic  efforts 
of  nature ;  those,  the  appointed  means  by  which 
the  harmony  and  order  of  creation  are  preserved. 
Those  of  us  who  have  merely  studied  the  brilliant 
phenomena  of  nature  appreciate  but  imperfectly 
the  grandeur  of  its  forces,  and  "those  of  us  who 
limit  our  appreciation  of  the  powers  of  oxygen  to 
the  energies  displayed  by  this  element  in  its  fully 
active  state,  form  but  a  very  inadequate  idea  of 
the  aggregate  results  accomplished  by  it  in  the 
economy  of  the  world."  Contemplate  the  amount 
of  oxygen  employed  in  the  function  of  respiration 
alone.  Faraday  has  roughly  estimated  that  the 
amount  of  oxygen  required  daily  to  supply  the 
lungs  of  the  human  race  is  at  least  one  thousand 


118  RELIGION   AND    CHEMISTRY.  [laser.  IV. 

millions  of  pounds ;  that  required  for  the  respira- 
tion of  the  lower  animals  is  at  least  twice  as  much 
as  this,  while  the  always  active  processes  of  decay 
require  certainly  no  less  than  four  thousand  mil- 
lions  of  pounds  more,  making  a  total  aggregate  of 
seven  thousand  millions  of  pounds  required  to 
carry  on  these  processes  of  nature  alone.  Com- 
pared with  this,  the  one  thousand  millions  of 
pounds  which,  as  Faraday  estimates,  are  sufficient 
to  sustain  all  the  artificial  fires  lighted  by  man, 
from  the  camp-fire  of  the  savage  to  the  roaring 
blaze  of  the  blast-furnace  or  the  raging  flames  of 
a  grand  conflagration,  seem  small  indeed. 

Amount  of  Oxygen  required  Daily.* 

Whole  population,  1,000,000,000 

Animals,  2,000,000,000 

Combustion  and  Fermentation,  1,000,000,000 

Decay  and  other  processes,  4,000,000,000 

Oxygen  required  daily,         =    8,000,000,000  Ibs. 

Tons. 

3,571,428  in  a  day. 
1,304,642,357  in  a  year. 

Whole  quantity,  1,178,158,000,000,000. 

•r 

How  utterly  inconceivable  are  these  numbers, 
which  measure  the  magnitude  of  nature's  processes, 
—  eight  thousand  millions  of  pounds  of  oxygen 
consumed  in  a  single  day !  When  reduced  to  tons, 

*  Taken  from  Faraday's  Lectures  on  the  Non-Metallic  Elements,  but 
correcting  an  obvious  error  in  reducing  the  pounds  to  tons. 


LECT.  IV.]  TESTIMONY   OF   OXYGEN.  119 

the  numbers  are  equally  beyond  our  grasp,  for 
it  corresponds  to  no  less  than  3,571,428  tons.  If 
such  be  the  daily  requisition  of  this  gas,  will  not 
the  oxygen  of  the  atmosphere  be  in  time  ex- 
hausted ?  It  is  not  difficult  to  calculate  approxi- 
mately the  whole  amount  of  oxygen  in  the  atmos- 
phere. It  is  equal  to  about  1,178,158  thousand 
millions  of  tons ;  a  supply  which,  at  the  present 
rate  of  consumption,  would  last  about  nine  hun- 
dred thousand  years.  We  need  not,  therefore,  fear 
that  the  amount  of  oxygen  in  the  atmosphere  will 
be  sensibly  diminished  in  our  day  or  generation; 
but  then  this  period,  immense  as  it  is,  is  not  to  be 
compared  with  the  ages  of  geological  time.  The 
time  which  has  elapsed  since  the  coal  we  are  now 
burning  was  deposited  in  its  beds  is  to  be  counted 
by  many  millions  of  years,  so  that  since  the  coal 
epoch  the  oxygen  of  the  atmosphere  must  have 
been  all  consumed  again  and  again.  Why,  then, 
has  it  not  all  been  removed  from  the  atmosphere  ? 
Simply  because,  in  the  beautiful  balance  of  creation, 
there  is  always  some  recuperative  process  for  every 
such  loss.  In  the  case  before  us,  it  is,  as  we  have 
seen,  the  vegetation.  As  fast  as  our  breath,  our 
fires,  and  the  process  of  decay  around  us  are  re- 
moving the  life-giving  oxygen,  just  so  fast  it  is 
restored  by  every  green  leaf  which  wraves  in  the 
sunshine,  and  by  every  blade  of  grass  which  sprouts 
under  our  feet.  What  the  animal  removes,  the 
plant  restores. 

I  have  before  stated  that,  in  the  process  of  de- 


Ozone. 


120  RELIGION   AND    CHEMISTRY.  [LKCT.  IV. 

cay,  the  oxygen  of  the  atmosphere,  which  is  ac- 
tive in  producing  the  change,  is  undoubtedly  in 
a  peculiarly  modified  condition,  a  con- 
dition in  which  its  affinities  are  high- 
ly exalted  even  at  the  ordinary  temperature  of 
the  air ;  and  I  also  stated  that  this  active  condi- 
tion of  the  element  is  apparently  maintained  by 
the  process  of  decay  itself.  This  subject  has  been 
greatly  elucidated  by  recent  discoveries.  Of  all 
the  known  processes  of  slow  combustion,  the  sim- 
plest and  the  most  active  is  the  slow  combustion 
of  phosphorus.  This  familiar  substance,  used  to  tip 
the  ends  of  lucifer  matches,  if  exposed  to  the  moist 
air,  slowly  combines  with  oxygen,  shining  at  the 
same  time  in  the  dark  with  a  peculiar  phospho- 
rescent light,  whence  the  name  of  the  substance, 
from  two  Greek  words,  signifying  light-bearer. 
The  process  is  therefore  entirely  analogous  to 
decay  and  respiration ;  but  since  phosphorus  is  a 
chemical  element,  the  change  is  far  simpler,  and 
can  be  more  readily  studied,  and  for  this  reason 
it  may  serve  to  elucidate  those  more  complex 
processes  of  nature. 

A  few  years  since,  Professor  Schonbein,  a  dis- 
tinguished Swiss  chemist,  discovered  that,  while  a 
stick  of  phosphorus  was  slowly  burning  in  a  jar 
of  moist  air,  a  portion  of  the  oxygen  present 
underwent  a  most  remarkable  change.  Without 
entering  into  the  details  of  these  experiments,  I 
will  simply  state  that,  when  thus  modified,  ordi- 
nary oxygen  seems  entirely  transformed.  The 


LECT.  IV.]  TESTIMONY   OF    OXYGEN.  121 

great  mass  of  the  oxygen  of  the  air,  as  you  will 
remember,  is  wholly  devoid  of  odor,  and  without 
action  on  the  most  delicate  organic  structures  or 
the  most  fleeting  vegetable  colors ;  but  when  thus 
treated  it  acquires  a  very  strong  and  pungent 
odor,  rapidly  rusts  polished  metals,  excites  decay 
in  organized  tissues,  and  at  once  bleaches  the 
most  permanent  dyes.  Could  there  be  a  more 
complete  inversion  of  properties  ?  One  of  the 
most  striking  characteristics  of  this  new  modifi- 
cation of  oxygen  is  its  peculiar  odor,  and  hence 
Schonbein  calls  it  ozone,  from  a  Greek  verb  sig- 
nifying to  smell.  Unfortunately,  up  to  this  time 
we  have  not  been  able  to  prepare  ozone  except 
in  a  very  dilute  condition,  for  the  most  active 
process  with  which  we  are  acquainted  does  not 
modify  more  than  ¥^7  of  the  whole  volume  of 
oxygen  employed ;  but  judging  from  its  action 
in  this  diluted  state,  pure  ozone  is  the  most  cor- 
rosive element  known. 

It  frequently  happens  that  a  great  discovery 
supplies  the  wanting  links  between  a  number  of 
obscure  facts,  and  thus  adds  quite  as  much  to  our 
knowledge  by  its  indirect  bearings  as  by  the  posi- 
tive additions  it  makes  to  the  general  stock.  So  it 
has  been  with  the  discovery  of  ozone.  Every  one 
who  has  used  an  electrical  machine  must  have  no- 
ticed the  peculiar  smell  which  follows  the  electrical 
discharge.  This  was  formerly  supposed  to  be  the 
odor  of  the  electrical  fluid  itself;  but  as  soon  as 
ozone  was  discovered,  the  odor  was  recognized  at 


122  RELIGION   AND    CHEMISTRY.  [LECT.  IV. 

once  as  belonging  to  this  new  agent,  and  it  was 
soon  ascertained  that  electricity  is  one  of  the  most 
efficient  means  of  modifying  the  oxygen  of  the  air. 
Moreover,  the  recent  investigations  of  Schonbein 
appear  to  prove  that  ozone  is  merely  electrified  oxy- 
gen. He  has  shown  that  there  are  two  varieties  of 
ozone,  corresponding  to  the  positive  and  negative 
electricities,  which  seem  to  have  the  power  of  en- 
tering into  chemical  union,  for  when  brought  to- 
gether they  neutralize  each  other,  and  ordinary 
passive  oxygen  is  the  result. 

Keturning  now  to  the  fact  that  the  slow  com- 
bustion of  phosphorus  throws  a  portion  of  the 
surrounding  oxygen  into  a  peculiar  condition,  in 
which  it  is  highly  active  in  producing  decay  and 
other  processes  of  oxidation,  —  it  certainly  seems 
probable  that  decay  and  respiration,  which  are 
also  examples  of  slow  combustion,  may  act  on 
the  air  in  the  same  way.  Moreover,  the  infer- 
ence that  ozone  is  the  active  agent  in  these  pro- 
cesses is  also  supported  by  the  fact  that  it  is 
always  present,  to  a  greater  or  less  extent,  in 
the  atmosphere,  although,  at  most,  in  exceedingly 
minute  quantities.  Observations  on  the  subject 
have  now  been  made  for  several  years,  and  from 
these  it  appears  that  the  quantity  of  ozone  in 
the  atmosphere  varies  with  the  season  and  with 
the  state  of  the  weather.  The  amount  has  been 
found  to  be  greater  at  night  than  during  the  day, 
and  greatest  just  before  sunrise.  It  is  greater  in 
winter  than  in  summer,  and  at  all  seasons  it  is 


LECT.IV.]  TESTIMONY   OF    OXYGEN.  123 

very  greatly  increased  during  stormy  weather, 
especially  during  a  snow-storm.  The  amount  is 
unusually  large  during  one  of  our  easterly  storms, 
and  during  a  thunder-shower  the  whole  surround- 
ing atmosphere  frequently  becomes  pervaded  with 
its  peculiar  odor,  especially  in  the  neighborhood 
of  the  place  where  lightning  has  struck. 

Ozone,  being  so  highly  corrosive,  cannot  be  pres- 
ent in  the  atmosphere  in  such  perceptible  quanti- 
ties without  producing  important  effects,  and  some 
persons  have  thought  not  only  to  refer  to  it  the 
various  processes  of  slow  combustion,  but  also  to 
trace  a  connection  between  the  prevalence  of  va- 
rious contagious  diseases  and  the  excess  or  defi- 
ciency of  ozone  in  the  air  of  the  infected  dis- 
trict ;  but  these  speculations  are  not  as  yet  based 
on  sufficient  evidence,  and  are  not  worthy  of  se- 
rious attention. 

Without,  however,  introducing  any  theories  not 
yet  fully  established  into  the  line  of  our  argument, 
this  much  is  clear.  Oxygen  gas  appears  in  nature 
in  three  conditions,  or  under  three  manifestations ; 
—  first,  entirely  passive,  as  in  the  great  mass  of  the 
air ;  secondly,  partially  active,  in  the  processes  of 
decay  and  respiration ;  thirdly,  highly  active,  in 
the  phenomena  of  combustion.  In  each  of  these 
conditions  its  properties  have  been  adjusted  with 
infinite  skill  and  delicacy,  on  the  one  hand  to  the 
thermal  and  electrical  conditions  of  the  globe,  and 
on  the  other,  to  the  constitution  of  man  and  of 
all  organic  nature. 


124  RELIGION   AND    CHEMISTRY.  [LECT.  IV. 

Here  I  must  conclude  my  brief  sketch  of  this 
wonderful  element.  If  I  have  succeeded  in  im- 
pressing on  your  minds  some  of  its  more  char- 
acteristic qualities,  if,  above  all,  you  have  become 
aware  how  exactly  and  delicately  these  qualities 
have  been  adjusted  to  the  scheme  of  creation, 
and  if  you  have  seen  how  the  smallest  perma- 
nent change  would  disturb  the  result,  —  this  is  all 
that  I  could  hope.  It  might  be  expected  that  the 
element  with  which  creative  power  built  up  the 
greater  part  of  our  globe,  -leaving  only  a  small 
excess  to  constitute  its  atmosphere,  would  furnish 
abundant  evidence  of  design,  and  how  fully  is  this 
expectation  realized !  Would  that  I  might  present 
to  you  the  evidence  more  forcibly !  But  it  is  pos- 
sible in  a  popular  lecture  only  to  touch  at  some  of 
the  more  striking  points,  and  I  have  felt  all  the 
time  like  a  school-boy  at  play,  in  spring,  in  some 
garden  rich  in  flowers,  snatching  here  and  there  a 
few  of  the  more  gaudy  tulips,  which  had  fully 
bloomed,  but  leaving  the  beautiful  and  delicate 
buds  all  unnoticed.  But  then  these  buds  of  knowl- 
edge shall  blossom,  and  when  the  summer  comes, 
the  rose  and  the  myrtle  will  fill  the  air  with  fra- 
grance, and  bear  a  still  sweeter  testimony  of  good- 
ness and  of  love. 


LECTUKE    Y. 

TESTIMONY   OF   WATER. 

THE  atmosphere,  as  you  will  remember,  consists 
mainly  of  two  permanent  and  elementary  gases; 
and  having  in  our  last  Lecture  discussed  the  func- 
tions of  its  active  element,  oxygen,  it  would  seem 
natural  to  consider  next  the  offices  of  nitrogen, 
that  most  singularly  inert  gas,  which  constitutes  no 
less  than  four  fifths  of  its  whole  mass ;  but  we  shall 
understand  more  clearly  the  complicated  relations 
of  this  truly  wonderful  substance,  associated  as  it 
is  with  all  the  higher  forms  of  corporeal  vitality, 
after  we  are  acquainted  with  two  of  the  remarkable 
cycles  in  nature,  in  which  the  water  and  carbonic 
acid  of  the  atmosphere  play  a  conspicuous  part.  It 
is  true  that  these  two  substances  are  very  variable 
constituents,  and  make  up  at  best  only  an  exceed- 
ingly small  fraction  of  the  whole  mass  of  the  air ; 
but  nevertheless,  they  discharge  functions  no  less 
important  than  those  of  oxygen  and  nitrogen,  and 
we  shall  find  that  they  are  equally  rich  in  illustra- 
tions of  the  wisdom  and  power  of  God. 

I  have  already  alluded  to  the  fact,  that  the  most 
striking  illustrations  of  creative  wisdom  have  been 
discovered  in  those  substances  which  are  the  most 
abundantly  distributed  through  nature,  and  which 


126  RELIGION   AND    CHEMISTRY.  [LECT.  V. 

are  the  most  intimately  associated  with  man,  and 
this  not  only  because  they  have  been  more  careful- 
ly studied,  but  also  because  they  have  the  most  im- 
portant functions  to  fulfil,  and  have  been  especially 
adapted  to  their  appointed  ends.  Of  no  substance 
is  this  principle  more  remarkably  true  than  it  is  of 
water.  As  you  well  know,  water  is  the  liquid  of  the 
globe,  and,  if  we  except  certain  transient  products 
of  volcanic  action,  it  is  the  only  liquid  which  exists 
naturally  on  its  surface.  Moreover,  it  is  in  constant 
circulation,  and,  like  the  bload  in  our  bodies,  is  the 
medium  through  which  nourishment  is  conveyed 
to  all  parts  of  organized  nature,  and  its  life  sustained. 
We  should  naturally  expect  that  a  substance  filling 
so  important  a  place  in  the  scheme  of  creation 
would  furnish  undoubted  evidences  of  design,  and 
it  will  be  my  object  in  the  present  Lecture  to  illus- 
trate a  few  of  the  more  striking  examples  of  adap- 
tation which  its  qualities  present,  beginning  with 
the  aeriform  condition  of  water  as  it  exists  in  the 
atmosphere. 

The  condition  of  the  atmosphere  of  aqueous  va- 
por, which  surrounds  the  globe,  differs  essentially 
The  aqueous  from  that  of  the  permanent  gases  which 
circulation.  are  simultaneously  present.  Oxygen  and 
nitrogen  cannot  be  reduced  to  liquids  even  by  the 
intense  cold  at  the  poles.  It  is  very  different  with 
aqueous  vapor.  The  slightest  reduction  of  temper- 
ature, when  the  air  is  saturated  with  moisture,  is 
sufficient  to  condense  a  portion  of  the  vapor  to 
water,  and  to  shower  it  on  the  earth  in  drops  of 


LECT.  V.]  TESTIMONY    OF   WATER.  127 

rain.  On  the  other  hand,  when  the  temperature 
rises,  the  heat  converts  more  water  into  vapor,  and 
the  aqueous  atmosphere  is  replenished.  Thus  it  is 
that  the  atmosphere  of  aqueous  vapor  on  the  earth 
is  liable  to  very  great  fluctuations,  from  which  the 
Creator  has  protected  the  great  mass  of  the  air  by 
endowing  oxygen  and  nitrogen  with  the  power  of 
retaining  the  aeriform  condition  under  all  circum- 
stances ;  and  we  shall  find  that  the  fluctuation  in 
the  one  case  is  as  important  as  the  stability  in 
the  other. 

I  stated  in  the  last  Lecture  that  our  atmosphere 
may  be  regarded  as  made  up  of  three  partial  at- 
mospheres, simultaneously  surrounding  the  globe, 
and  as  was  the  case  with  the  atmosphere  of  oxygen, 
we  shall  best  understand  the  fluctuations  of  the 
aqueous  atmosphere  if  we  begin  by  eliminating  for 
a  moment  from  our  thoughts  the  other  two.  In 
order  to  make  the  subject  clear,  it  will  be  neces- 
sary for  me  to  dwell  very  briefly  on  a  few  well  es- 
tablished facts  in  meteorology,  which,  although  not 
very  interesting  in  themselves,  will  unfold  to  us 
some  of  the  beautiful  provisions  of  nature  by  which 
the  aqueous  circulation  on  the  globe  is  maintained. 

If  there  were  no  free  oxygen  or  nitrogen  gas,  the 
earth  would  still  be  surrounded  with  an  atmosphere 
of  aqueous  vapor,  and  we  are  able  to  foresee,  in 
some  small  measure,  what  the  conditions  of  such  an 
atmosphere  would  be.  Its  density  at  the  sea  level 
would  depend  chiefly  on  the  temperature,  and 
would  therefore  vary  very  rapidly  with  the  latitude, 


128 


KELIGION   AND    CHEMISTRY. 


[LECT.  V. 


and  would  be  constantly  changing  at  the  same  lo- 
cality with  the  alternations  of  the  climate.  We  are 
able  to  determine  approximately  what  the  density 
would  be  at  any  given  temperature,  and  a  few  of 
the  results  are  included  in  the  following  table. 

Weight  at  the  Sea  Level  of  one  Cubic  Foot  of  Vapor. 


perature. 
tirenheit. 

Weight. 
Grains. 

Temperature. 
Fahrenheit. 

Weight. 
Grains. 

Temperature. 
Fahrenheit. 

Weight. 
Grains. 

0° 

0.78 

40° 

3.09 

70°     . 

8.00 

10° 

1.11 

50° 

4.28 

80° 

10.81 

20° 

1.58 

60° 

5.87 

90° 

14.50 

30° 

2.21 

It  is  evident  from  these  numbers,  that  a  very 
small  change  of  temperature  would  cause  immense 
fluctuation  in  such  an  atmosphere.  At  0°  one  cu- 
bic foot  of  the  aqueous  atmosphere  could  contain 
only  about  three  fourths  of  a  grain  of  vapor,  while 
at  80°  it  could  contain  fifteen  times  as  much,  and 
hence,  although  under  the  tropics  the  density  of  our 
assumed  atmosphere  would  be  comparatively  large, 
there  would  be  almost  a  complete  vacuum  at  the 
poles.  Into  this  vacuum  the  vapor  would  flow  from 
the  equator,  and  thus  in  either  hemisphere  there 
would  result  a  perfect  torrent  of  vapor  rushing  to- 
wards the  north  or  south.  But  it  is  also  evident 
that,  as  this  current  became  chilled  in  passing 
through  the  cooler  climate  of  the  temperate  zone 
the  vapor  would  gradually  condense  to  water,  which, 
falling  on  the  land  or  on  the  ocean,  would  return 
in  time  to  the  equator,  ready  to  begin  again  the 
same  succession  of  ceaseless  changes. 


LECT.V.]  TESTIMONY    OF   WATER.  129 

Although  the  presence  of  the  air  materially  mod- 
ifies, it  does  not  essentially  change,  the  aqueous  cir- 
culation. The  air  retards  the  formation  of  vapor, 
but  does  not  prevent  it,  and  at  any  given  tempera- 
ture the  same  amount  of  water  will  evaporate  into 
a  given  space,  whether  it  be  a  perfect  vacuum  or 
filled  with  air.  Thus,  for  example,  when  air  at  80° 
is  saturated  with  moisture,  it  contains,  as  before, 
exactly  10.81  grains  of  vapor,  and  the  table  just 
given  applies  equally  well  to  the  actual  condition 
of  the  globe,  covered  with  its  dense  atmosphere  of 
oxygen  and  nitrogen,  as  to  the  case  just  assumed. 
There  is,  however,  a  most  important  difference  be- 
tween the  two  conditions,  —  a  difference  on  which 
the  adaptation  of  the  system  of  aqueous  circulation 
in  the  order  of  nature  entirely  rests. 

Were  there  no  air  on  the  globe,  the  quantity 
of  vapor  would  adjust  itself  almost  instantaneously 
to  any  variation  of  temperature,  and  the  maxi- 
mum amount  possible  would  always  be  present  at 
any  given  place.  An  elevation  of  temperature 
would  be  attended  by  rapid  evaporation,  and  the 
amount  of  water  required  to  fill  the  space  would 
suddenly  flash  into  vapor ;  while,  on  the  other 
hand,  a  corresponding  depression  of  temperature 
would  be  accompanied  with  an  equally  sudden  pre- 
cipitation of  the  excess  of  water  which  the  air 
could  no  longer  contain,  not  in  genial  showers  or 
diffusive  rain,  but  in  terrific  torrents,  of  which  the 
deluging  showers  of  the  tropics  can  give  us  only  a 
feeble  conception  \  for  the  drops,  falling  without 


130  RELIGION   AND    CHEMISTRY.  [LECT.  V. 

resistance,  would  be  as  destructive  in  their  effects 
as  volleys  of  leaden  shot. 

In  the  actual  condition  of  the  atmosphere,  the 
presence  of  a  dense  medium  very  greatly  retards 
these  changes,  and  although  it  does  not 
alter  their  essential  nature,  it  moderates 
their  action  and  mitigates  the  violence  of  their  ef- 
fects. An  elevation  of  temperature  is  followed  by 
an  evaporation  of  water  into  the  air ;  but  the  pro- 
cess is  comparatively  slow,  and  it  is  a  long  time  be- 
fore the  air  is  fully  saturated.  So  also  when  the  air 
is  saturated,  a  depression  of  temperature  is  followed 
by  the  condensation  of  a  portion  of  the  vapor  into 
rain;  but  here  again  the  mass  of  the  atmosphere 
tempers  the  abruptness  of  the  transition,  and  al- 
lays its  violence.  The  vapor  condenses  first  into 
vesicles,  which  are  minute  hollow  bubbles  of  water, 
so  light  that  they  float  in  the  atmosphere,  and 
when  these  bubbles  break,  and  the  drops  of  rain 
fall,  they  again  are  wafted  down  so  slowly  through 
the  resisting  medium,  and  alight  so  softly,  that  the 
"  soft  falling  snow  and  the  diffusive  rain "  have 
become  fit  emblems  of  the  beneficence  of  God,  as 
they  give  the  strongest  evidences  of  his  wisdom 
and  skill.  Moreover,  the  glorious  clouds,  which 
add  so  much  to  the  beauty  of  the  landscape,  and 
typify  in  their  virgin  whiteness  the  purity  of 
heaven,  are  only  collections  of  these  vesicles  of 
water  floating  in  the  upper  atmosphere,  and  mark 
the  stage  of  transition  between  vapor  and  rain ;  and, 
further  still,  it  is  probable,  as  I  stated  in  a  previous 


LECT.  V.]  TESTIMONY   OF   WATER.  131 

Lecture,  that  it  is  these  same  minute  vesicles  which 
tint  the  morning  and  evening  sky  with  their  gor- 
geous hues  and'  cover  our  earthly  dwelling-place 
with  its  canopy  of  blue. 

Again,  the  presence  of  the  air  very  greatly  re- 
tards the  aqueous  circulation  above  described,  with- 
out altering  its  essential  character.  There  is  now 
the  same  great  difference  between  the  density  of 
the  atmosphere  of  vapor  at  different  latitudes,  as 
if  it  were  the  only  atmosphere  on  the  globe,  and 
the  dense  vapor  of  the  tropics  tends  constantly  to 
flow  towards  either  pole ;  but  as  it  cannot  move 
without  carrying  with  it  the  whole  mass  of  the 
atmosphere,  this  tendency  merely  increases  the 
velocity  of  those  great  aerial  currents  already  de- 
scribed in  a  previous  Lecture.  Still  the  general 
fact  remains  the  same.  From  the  whole  surface 
of  the  globe  water  is  constantly  evaporating  into 
the  aqueous  atmosphere  which  surrounds  it.  The 
heated  air  from  the  tropics,  heavily  charged  with 
moisture,  is  continually  mdving  towards  the  colder 
regions,  both  of  the  north  and  of  the  south ;  and 
as  the  current  thus  becomes  chilled,  the  vapor  is 
slowly  condensed,  and  the  water  showered  down  in 
fertilizing  rains  on  the  land.  Thus  it  is  that  those 
beautiful  provisions  which  we  see  in  the  rain  all 
depend  on  the  presence  of  the  air,  and  result  from 
a  careful  adjustment  of  the  properties  of  aqueous 
vapor  to  the  exact  density  of  our  atmosphere. 
"  Hath  the  rain  a  Father  ?  "  Science,  by  discover- 
ing these  evidences  of  skilful  adaptation,  has  most 


132  KELIGION   AND    CHEMISTRY.  [LECT.  V. 

conclusively  answered  this  question,  and  the  answer 
is  the  same  now  as  in  the  days  of  Job.     a  Behold, 

"  God  is  great He  maketh  small  the  drops 

"  of  water :  they  pour  down  rain  according  to  the 
"vapor  thereof." 

But  what  becomes  of  the  rain  ?  Would  that  I 
could  answer  this  question  satisfactorily.  We  all 
understand  the  general  theory  of  the  aqueous  cir- 
culation, but  the  deepest  philosophy  and  the  keen- 
est science  are  not  able  to  fathom  its  details,  or  to 
comprehend  in  their  fulness  the  world  of  wonder- 
ful adaptations  which  the  question  unfolds.  We 
all  know  that  the  drops  of  rain  percolate  through 
the  soil,  and  collect  in  natural  reservoirs  formed 
between  the  layers  of  rock,  and  that  these  reser- 
voirs supply  the  springs.  The  rills  from  numerous 
adjacent  springs  unite  to  form  a  brook,  which  in- 
creases as  it  flows,  until  it  finally  becomes  the  ma- 
jestic river,  rolling  silently  on  its  course.  Every 
drop  of  that  water  has  been  an  incessant  wanderer 
since  the  dawn  of  creation,  and  it  will  soon  be 
merged  again  in  the  vast  ocean,  only  to  begin 
anew  its  familiar  journey.  If  you  would  gain  an 
idea  of  the  magnitude  and  extent  of  this  won- 
derful circulation,  you  must  bring  together  in  im- 
agination all  the  rivers  of  the  world,  the  Amazon 
and  the  Orinoco,  the  Nile  and  the  Ganges,  the  Mis- 
sissippi and  the  St.  Lawrence,  and,  adding  to  these 
the  ten  thousands  of  lesser  streams,  endeavor  to 
form  a  conception  of  the  incalculable  amount  of 
water  which  during  twenty-four  hours  they  pour 


LECT.  V.]  TESTIMONY   OF   WATER.  133 

into  the  vast  basin  of  the  world,  and  then  remem- 
ber that  during  the  same  period  at  least  four  times 
as  much  water  must  have  been  raised  in  vapor, 
and  scattered  in  rain  over  the  surface  of  the  land. 
Would  you  form  an  idea  of  the  importance  of  this 
circulation,  you  must  not  limit  your  appreciation 
to  its  economical  value,  as  a  great  source  of  power, 
working  the  mills  and  the  forges  of  civilized  man, 
and  building  up  vast  marts  of  manufacturing  in- 
dustry, nor  must  you  regard  alone  its  commer- 
cial value,  bearing  as  it  does  on  its  bosom  to  the 
ocean  the  freights  of  empires.  These  applications 
of  power,  however  important  in  themselves,  are 
insignificant  in  extent  compared  with  those  mighty 
agencies  which  the  aqueous  circulation  is  constant- 
ly exerting  in  nature.  It  has  been  the  great  agent 
of  geological  changes :  here  washing  away  conti- 
nents, and  there  building  them  up ;  here  gullying 
out  valleys,  and  there  smoothing  away  inequalities 
of  surface ;  here  dissolving  out  the  particles  of 
metals  from  the  solid  rocks,  and  there  collecting 
them  together  in  beds  of  useful  ores.  It  has  cov 
ered  the  earth  with  verdure  and  animal  life,  by  con- 
veying nourishment  to  the  plant  and  food  to  the 
animal.  It  sustains  our  own  bodies,  for  it  is  a  por- 
tion of  this  very  circulation  which  ebbs  and  flows 
in  our  veins,  and  whose  pulsations  beat  out  the 
moments  of  our  lives ,  and  could  I  bring  together 
in  one  picture  the  infinite  number  of  beneficent 
ends  which  it  has  been  made  by  Providence  to  sub- 
serve, I'  am  sure  that  you  would  agree  with  me 


134  RELIGION   AND    CHEMISTRY.  [LECT.  V. 

that  there  is  not  in  nature  stronger  evidence  of 
design  than  in  the  adaptations  of  this  simple  and 
familiar  liquid. 

In  order  that  we  may  appreciate  in  some  humble 
measure  the  force  of  this  evidence,  let  us  consider 
some  of  the  qualities  of  water ;  but  at  the  same 
time  let  us  not  forget  that  the  strength  of  our 
argument  lies  not  so  much  in  the  fact  that  each 
property  has  been  skilfully  adjusted  to  some  spe- 
cific end,  as  it  does  in  the  harmonious  working  of 
all  the  separate  details.  Had  man  creative  power, 
the  first  would  fall  within  the  range  of  his  intelli- 
gence ;  but  to  adapt  the  same  substance  to  a  thou- 
sand different  ends,  and  to  adjust  each  of  its  prop- 
erties to  a  thousand  different  conditions,  covering 
with  their  complex  network  all  the  known  uni 
verse,  implies  a  power  nothing  less  than  infinite, 
and  an  intelligence  nothing  lower  than  divine.  It 
is  evident,  however,  that  we  can  gain  a  knowledge 
of  the  general  plan  only  by  studying  the  details, 
and  unfortunately  it  is  to  these  details  that  our  ac- 
curate knowledge  is  almost  entirely  confined.  We 
can  see,  for  example,  that  each  property  of  water 
has  been  designed  for  some  specific  purpose.  We 
can  also  recognize  the  evident  fact,  that  all  the 
properties  work  harmoniously  together  in  the  gen- 
eral scheme  of  nature ;  but,  in  the  present  state  of 
knowledge,  to  trace  the  intimate  relations  of  these 
properties  is  frequently  as  impossible  as  it  is  to 
form  a  clear  conception  of  the  coexistence  and  har- 
monious action  of  all.  Yet  in  these  very  facts  lies 


Water  a  oon- 


LECT.  V.]  TESTIMONY    OF   WATER.  135 

the  whole  force  of  the  argument  from  design,  and 
it  is  only  the  limitations  of  our  knowledge  and 
faculties  which  weaken  the  impression  on  our 
minds.  But  were  these  limitations  removed,  all 
argument  would  become  unnecessary,  for  then  rea- 
soning would  be  exchanged  for  vision,  and  in  the 
refulgence  of  the  Divine  Presence  we  should  know 
even  as  we  are  known. 

It  is  a  familiar  fact,  that  moisture  is  an  essential 
condition  of  organic  life  ;  but  few  persons,  I  sus- 
pect, are  aware  that  this  familiar  liquid 
constitutes  the  greater  part  of  all  organ- 
ized  beings.  The  physical  man  has  been  gam 
described  by  one  writer  as  consisting  of  merely  a 
few  pounds  of  solid  matter  distributed  through  six 
pailfuls  of  water,  and  it  is  a  fact  that  no  less  than 
four  fifths  of  these  bodies  of  ours  are  made  up  of 
water.  Yet  this  is  a  small  proportion  compared 
with  the  amount  which  enters  into  the  structure 
of  most  of  the  lower  animals.  Some  of  these,  such 
as  the  medusae,  —  sunfishes,  —  are  little  else  than 
organized  water.  Professor  Agassiz  obtained  from 
one  of  the  large  sunfishes  found  on  our  coast, 
weighing,  thirty  pounds,  only  two  hundred  and 
forty  grains  of  solid  matter  ;  and  we  may  safely  say 
that  at  least  nine  hundred  and  ninety-nine  parts  in 
a  thousand  of  these  singular  animals  consist  of 
water.  Water  constitutes  to  almost  as  great  an 
extent  most  of  the  vegetable  products  which  are 
articles  of  food,  as  will  be  seen  by  the  accompany- 
ing table. 


136  RELIGION   AND    CHEMISTRY.  [LECT.  V. 

Plums  contain  75  per  cent  of  water. 

Potatoes  "  75  "  "  « 

Apples  "  80  «  "  « 

Carrots  «  83  «  «  « 

Turnips  "  90  "  "«  « 

Watermelons     "  94  «  «  « 

Cucumbers  "  97  "  «  « 

It  is  evident  from  these  facts,  that  water  is  the 
chief  material  of  which  all  organized  structures 
are  formed,  and  in  studying  the  aqueous  circula- 
tion we  have  already  become  acquainted  with  the 
beautiful  provisions  of  nature  by  which  this  life- 
giving  liquid  is  distributed  over  the  earth,  and 
showered  down  upon  the  meadow  and  forest  alike. 
Without  water  organic  life  cannot  exist,  and  where 
from  any  local  causes  the  supply  fails,  there  we  find 
a  barren  wilderness ;  while,  on  the  other  hand,  the 
genial  influences  of  the  rain  will  soon  make  even 
"  the  desert  blossom  as  the  rose."  It  is  a  remarkable 
fact  of  physical  geography,  that  the  distribution 
of  water  by  the  aqueous  circulation  is  rendered 
more  effective  by  the  peculiar  structure  of  the 
continents,  and  the  position  of  the  great  moun- 
tain-chains. 

"The  mountain-chains,"  writes  Professor  Guyot, 
in  his  excellent  work  on  "Earth  and  Man,"  "are 
great  condensers  placed  here  and  there  along  the 
continents  to  rob  the  winds  of  their  treasures,  and 
to  serve  as  reservoirs  for  the  rain-waters,  and  to 
distribute  them  afterwards  as  they  are  needed  over 


LECT.V.]  TESTIMONY   OF   WATER.  137 

the  surrounding  plains.  Their  wet  and  cloudy 
summits  are  untiringly  occupied  with  this  impor- 
tant work,  and  from  their  sides  flow  numberless 
torrents  and  rivers,  carrying  in  all  directions  wealth 
and  life." 

Thus  the  mountains,  whose  majestic  forms  affect 
so  powerfully  the  human  soul,  and  which  have  ex- 
erted such  an  influence  on  the  history  of  the  race, 
are  also  among  the  most  beneficent  means  in  the 
Divine  Providence  by  which  the  earth  has  been 
fertilized  and  rendered  a  fit  abode  for  man.  More- 
over, these  mountain-chains  have'  been  evidently 
so  distributed  as  to  give  the  greatest  efficiency  to 
the  aqueous  circulation,  and  to  irrigate  the  conti- 
nents most  effectively  with  their  fertilizing  floods. 
"We  cannot  therefore  suppose  that  even  these 
ridges  on  the  earth's  surface,  which  are  the  lasting 
records  of  ancient  geological  changes,  were  fixed 
by  chance,  for  they  also  bear  traces  of  His  intelli- 
gence who  seeth  the  end  from  the  beginning,  and 
every  part  of  whose  works  is  adapted  to  every 
other.  "Lord,  thou  hast  been  our  dwelling-place 
"in  all  generations.  Before  the  mountains  were 
K  brought  forth,  or  ever  thou  hadst  formed  the  earth 
K  and  the  world,  even  from  everlasting  to  everlasting, 
"thou  art  God." 

But  it  is  not  the  mountains  alone  which  condense 
the  vapor  of  the  atmosphere ;  for  under  certain 
conditions  the  level  plains  act  in  a  similar 
way,  and  distil  down  the  precious  drops  of 
dew  upon  field  and  meadow,  distributing  it  among 


138  RELIGION   AND    CHEMISTRY.  [LECT.  V. 

the  plants  with  discriminating  care  for  the  necessi- 
ties of  each.  The  dew  is  simply  another  phase  of 
the  great  aqueous  circulation,  and  like  the  rain  it  is 
a  persuasive  witness  of  the  wisdom  of  the  Divine 
Disposer,  who  has  adjusted  its  amount  to  the  wants 
of  the  vegetable  world.  Every  one  has  noticed 
the  deposition  of  moisture  on  a  pitcher  of  ice-cold 
water  during  a  summer's  day,  and  in  this  familiar 
fact  we  have  at  once  an  example  and  an  illustra- 
tion of  the  simple  provision  by  which,  during  even 
the  long  droughts  of  summer,  the  plants  receive 
a  partial  supply  of  water,  sufficient  at  least  to  sus- 
tain their  life  until  the  later  rains  bring  the  autumn 
fruits  to  maturity,  and  stimulate  a  more  vigorous 
growth. 

The  explanation  of  the  dew  upon  the  pitcher  is 
very  simple.  The  layer  of  air  in  contact  with  its 
cold  mass  is  rapidly  cooled,  and  when  it  can  no 
longer  hold  all  the  moisture  it  contains,  the  excess 
is  deposited  in  drops  on  the  surface.  Exchange 
now  the  pitcher  for  the  earth,  and  you  have  at  once 
an  explanation  of  the  proximate  cause  of  the  dew. 
After  sunset  the  earth,  like  the  pitcher,  cools  down 
the  layer  of  atmosphere  immediately  in  contact  with 
it  to  such  a  degree  that  the  whole  of  the  vapor  can 
no  longer  retain  its  aeriform  condition.  As  a  neces- 
sary result,  a  portion  is  condensed  and  deposited  up- 
on the  surface,  and  this  is  what  we  call  dew.  But  it 
will  be  asked,  What  cools  the  earth  so  suddenly  after 
the  setting  of  the  sun  ?  for  this  is  not  so  evident  as 
the  cause  of  the  coldness  of  the  pitcher.  Certainly 


LECT.  V.]  TESTB10NY   OF   WATER.  139 

not,  and  the  question  will  lead  us  to  a  study  of  those 
relations  in  which  the  adaptations  to  be  discovered 
in  this  natural  phenomenon  are  chiefly  to  be  found. 

The  earth,  as  I  stated  in  the  second  Lecture,  is 
moving  with  immense  rapidity  through  a  space, 
whose  temperature  is  at  least  270  degrees  below  the 
zero  of  Fahrenheit's  thermometer,  and,  like  a  heated 
cannon-ball  hung  in  the  middle  of  a  cold  room,  it  is 
continually  losing  heat  by  radiation.  The  dense 
atmosphere  with  which  it  is  enveloped,  acting,  as  we 
have  seen,  like  a  blanket,  protects  the  earth  from 
the  intense  cold  of  space  to  a  certain  extent ;  but 
still  the  constant  loss  of  heat  is  so  great,  that,  were 
the  sun's  rays  withheld  for  a  few  days,  the  tem- 
perature of  the  surface-land,  even  in  the  tropics, 
would  fall  as  low  as  it  is  now  at  the  poles  during 
the  long  night  of  the  arctic  winter.  In  the  day- 
time the  earth  receives  from  the  sun  more  heat 
than  it  loses ;  but  when  this  great  thermal  source 
is  temporarily  withdrawn,  the  loss  of  heat  continu- 
ing as  rapidly  as  before,  the  surface  becomes  quickly 
cooled,  and  the  deposition  of  dew  follows,  as  just 
explained ;  or,  if  the  temperature  falls  below  the 
freezing  point,  the  dew  is  changed  to  frost. 

You  must  all  have  noticed  that  the  most  copious 
deposition  both  of  dew  and  frost  takes  place  on  clear 
nights,  and  that  during  cloudy  weather  this  supply 
of  moisture  is  entirely  withheld.  The  reason  is 
obvious.  The  earth  loses  heat  by  radiation,  and 
the  clouds,  intercepting  the  rays,  reflect  them  back 
to  the  earth.  A  shed  or  any  other  protection 


140  RELIGION   AND    CHEMISTRY.  [LEGT.  V. 

spread  over  the  ground  acts  in  the  same  way,  and 
it  is  well  known  that  a  covering,  however  slight,  is 
sufficient  to  protect  tender  plants  from  the  blight 
of  the  early  frosts.  Can  it  then  be  an  accident,  a 
mere  result  of  chance,  that  the  dew  is  deposited 
most  abundantly  where  it  is  needed  most,  and  that 
this  supply  of  moisture  fails  only  when  the  clouds 
promise  a  more  copious  draught  of  liquid  nourish- 
ment from  the  rain  ? 

There  is  still  another  fact  presented  by  the  dew, 
which  is  equally  suggestive.  The  heavens  do  not 
distil  down  their  liquid  treasures  upon  all  objects 
alike,  but  the  dew  is  deposited  much  more  abun- 
dantly on  the  herbage,  the  shrubs,  and  the  trees, 
which  need  the  refreshing  moisture,  than  on  fallow 
land,  the  sandy  plain,  or  the  beaten  road ;  and  here 
again  the  cause  has,  been  discovered.  It  is  evident 
from  the  general  theory  of  the  subject,  that  the  lar- 
gest amount  of  dew  will  fall  on  the  coldest  surface, 
and  it  is  equally  obvious  that,  other  things  being 
equal,  those  objects  will  cool  most  rapidly  which 
have  the  smallest  supply  of  heat  to  lose,  and  which 
radiate  it  with  the  greatest  freedom.  Now  it  has 
been  ascertained  by  experiment,  that  the  facility  of 
radiating  heat  depends  entirely  on  the  nature  of 
the  surface,  and  the  surfaces  of  leaves  have  such  a 
remarkable  power  in  this  respect,  that  it  would  seem 
as  if  they  were  specially  designed  for  the  purpose. 
If  next  you  consider  how  small  a  quantity  of  mat- 
ter the  leaves  contain  compared  with  their  large  ra- 
diating surfaces,  you  will  see  that  there  are  all  the 


LECT.  V.]  TESTIMONY    OF  WATER.  141 

conditions  present  of  rapid  cooling.  When,  there- 
fore, under  a  clear  evening  sky,  the  rays  of  heat 
are  escaping  from  all  objects  into  the  celestial  space, 
the  green  foliage  soon  becomes  colder  than  the  bar- 
ren rocks  or  the  inanimate  clod,  and  receives  in  con- 
sequence a  greater  supply  of  dew. 

It  will  be  remembered,  as  I  stated  in  the  second 
Lecture  of  this  course,  that  the  points  of  leaves  have 
the  power  of  silently  discharging  the  thunderbolts 
of  heaven,  and  that  in  consequence  every  tree  acts 
far  more  efficiently  to  avert  the  stroke  of  this 
destructive  agent  than  the  best  constructed  light- 
ning-rod. Is  not  now  the  force  of  this  evidence 
of  adaptation  very  greatly  enhanced,  when  we  find 
that  the  surfaces  of  these  same  leaves  have  been 
endowed  with  an  equally  remarkable  power  of  ra- 
diating heat,  by  which  they  are  insured  a  daily 
supply  of  moisture  when  they  need  it  most? 
Could  the  adaptation  of  the  structure  of  the  leaf  to 
these  two  entirely  distinct  physical  conditions  of 
the  atmosphere  be  the  result  of  anything  but  in- 
telligence ?  Admitting  that  we  can  possibly  con- 
ceive, —  as  Mr.  Darwin  and  the  modern  advocates 
of  the  development  theory  would  have  us  believe, 
—  that  under  the  pressure  of  circumstances  a  plant 
may  have  the  power  of  changing  its  structure  so  as 
to  adapt  it  to  the  external  conditions,  still  I  think 
no  one  will  be  so  bold  as  to  maintain  that  there 
can  be  any  brute  agency  in  vegetation  endowed 
with  such  foresight  as  to  have  adapted  the  material 
and  structure  of  each  leaf  from  the  very  first  to 


142  KELIGION  AND    CHEMISTRY.  [LECT.  V. 

the  physical  conditions  of  the  globe,  and  this,  more- 
over, for  the  purpose  of  effecting  ends  so  remotely 
connected  with  its  own  organization  as  the  dis- 
charge of  electricity  or  the  radiation  of  heat.  If 
this  can  result  from  chance,  under  its  modern  name 
of  natural  selection,  then  chance  is  but  a  counter- 
feit name  of  God.  Gideon  believed  that  God  would 
save  Israel,  because  the  dew  fell  on  the  fleece  but 
not  on  the  ground,  and  afterwards  on  the  ground 
but  not  on  the  fleece,  and  shall  we  doubt  the  reality 
of  the  Divine  Providence,  before  whom  a  similar 
miracle  is  repeated  every  evening,  with  such  benefi- 
cent results  ?  If  it  be  the  mark  of  intelligence  to 
be  able  to  fathom  and  comprehend  this  wonder  of 
Nature,  can  it  be  anything  below  Infinite  Intelli- 
gence "  who  hath  begotten  the  drops  of  dew  "  ? 

I  might  with  advantage  enter  more  into  detail  in 
regard  to  the  laws  of  the  distribution  both  of  the 
rain  and  of  the  dew,  but  time  and  space  forbid.  I 
have  been  able  only  to  open  the  subject ;  yet  if  I 
have  succeeded  in  impressing  you  with  the  extent 
of  the  field  which  these  beautiful  phenomena  pre- 
sent to  your  inquiry,  it  is  all  that  I  could  expect. 
"We  have  seen  that  it  is  through  these  familiar  chan- 
nels that  liquid  nourishment  is  conveyed  to  the  or- 
ganic world,  and  the  reservoirs  supplied  which  feed 
the  great  river-system  of  the  globe.  But  we  should 
form  a  very  imperfect  idea  of  the  resources  of  na- 
ture were  we  to  limit  our  regards  of  the  aqueous 
circulation  to  this  important  use.  The  life-blood  of 
our  bodies,  which  conveys  to  each  muscle  the  nour- 


LECT.  V.]  TESTIMONY   OF   WATER.  143 

ishment  it  requires,  when  it  returns  again  through 
the  veins,  this  errand  well  done,  is  no  less  usefully 
employed  in  carrying  away  the  portions  Waterthe 
of  the  tissues  which  have  been  worn  out  in  great  purifier- 
the  processes  of  life ;  and  where  from  any  cause  this 
last  function  is  not  faithfully  discharged,  and  the 
wasted  muscles  are  allowed  to  remain  in  the  sys- 
tem, disease  and  death  are  the  inevitable  results. 
So  also  is  it  with  the  life-liquid  of  nature,  which  in 
the  rain  and  the  dew  carries  food  to  the  whole  or- 
ganic world.  When  this  office  has  been  fulfilled,  it 
returns  again  to  the  ocean,  washing  away  those 
waste  products  of  organic  life,  which,  if  they  re- 
mained, would  cause  pestilence  and  general  decay. 
It  is  true  that  we  cannot  trace  all  the  details  of 
this  cleansing  process ;  but  you  need  not  the  aid  of 
science  to  assure  you  of  the  general  facts.  Let  the 
free  flowing  of  the  rain-water  be  interrupted,  and 
you  well  know  that  stagnant  pools,  breeding  pesti- 
lence, or  deadly  swamps,  exhaling  malaria,  are  the 
immediate  results.  I  cannot  overstate  the  impor- 
tance of  this  function  of  the  aqueous  circulation,  or 
too  strongly  insist  on  the  evidence  of  wisdom  which 
the  adaptation  of  the  properties  of  water  to  this 
beneficent  end  implies.  It  is  the  great  cleansing 
agent  of  the  world.  Wherever  it  flows,  there  it  pu- 
rifies, and  its  limpid  streams,  clear  as  crystal,  are  fit 
emblems  of  the  purity  of  heaven.  Hence  the  sig- 
nificance of  this  liquid  in  all  religious  systems.  The 
ancient  Egyptians  worshipped  the  water  of  the  Nile, 

and  the  Hindoo  idolaters  of  the  present  day  rever- 

10 


144  RELIGION   AND    CHEMISTRY.  [LECT.  V. 

ence  with  equal  devotion  the  water  of  the  Ganges. 
Passing  to  Judaism,  we  find  the  washing  with  water 
enjoined  as  a  sacred  duty  by  the  Hebrew  law ;  and 
lastly,  in  the  Christian  dispensation  the  pure  liquid 
has  become  the  medium  of  its  most  sacred  rite,  and 
the  outward  washing  of  baptism  typifies  that  in- 
ward "washing  of  regeneration,"  by  which  alone 
man  is  saved. 

Glancing  now  for  a  single  moment  at  the  aesthet- 
ic aspects  of  the  subject,  consider  what  sources  of 
pleasure  the  varied  phases  of  the  aqueous  circula- 
tion furnish,  and  what  an  influence  on  the  soul  of 
man  they  are  calculated  to  exert.  The  bubbling 
spring,  the  purling  rill,  the  murmuring  brook,  the 
sparkling  cascade,  the  roaring  torrent,  the  majesti- 
cally flowing  river,  are  familiar  images  of  poetry, 
and  the  occasions  of  mental  emotions  which  all  have 
experienced  and  none  can  fully  describe,  while  the 
mighty  cataract  and  the  ocean-storm  are  among 
the  sublimest  aspects  of  nature,  and  inspire  the  be- 
holder with  reverence  and  awe.  When,  now,  you 
reflect  that  the  chords  of  the  human  soul  have  been 
so  strung  as  to  vibrate  in  sympathy  with  these  emo- 
tions of  the  material  creation,  and  that  thus  the 
aqueous  circulation  has  been  made  a  means  of  in- 
structing and  elevating  the  human  race,  can  you  re- 
fuse to  accept  the  evidence  of  wisdom  and  goodness 
which  a  system  so  far-seeing  in  its  design,  and  so 
beneficent  in  its  results,  affords  ? 

The  mechanism  of  nature  differs,  as  we  have 
seen,  from  the  creations  of  human  ingenuity,  in  the 


LECT.  V.]  TESTIMONY   OP   WATER.  145 

fertility  of  its  resources.  Man  combines  numerous 
means  in  order  to  produce  a  single  end ;  but  in 
nature  the  most  varied  and  apparently  incompat- 
ible results  flow  from  a  single  design.  In  God's 
works  the  means  are  employed,  not  as  we  use  them 
in  the  poverty  of  our  resources,  but  from  the  exu- 
berance of  riches.  To  use  the  language  of  another, 
"All  the  means  are  ends,  and  all  the  ends  are 
means";  and  the  grand  result  is  an  harmonious  sys- 
tem, in  which  every  part  is  a  whole,  and  where  the 
whole  that  is  known  is  felt  to  be  only  a  very  insig- 
nificant part.  Such  is  the  character  of  the  aqueous 
circulation,  which  we  are  now  studying,  and  assur- 
edly the  numerous  results  we  have  already  seen 
flowing  from  this  simple  mechanism  are  sufficient 
to  mark  the  system  as  Divine ;  but  we  have  not  as 
yet  exhausted  its  resources.  Indeed,  we  have  been 
all  the  time  looking  at  only  one  side  of  the  design, 
and  there  is  a  whole  set  of  adaptations  yet  unno- 
ticed, which  are  no  less  important  in  the  scheme  of 
organic  nature  than  those  we  have  so  briefly  consid- 
ered ;  and  when  we  have  become  acquainted  with 
these,  we  shall  find  still  other  phases  of  this  bound- 
less plan  presented  to  our  view,  and  not  until  man 
ceases  to  learn  by  study,  or  the  waters  cease  to  roll, 
will  the  subject  be  exhausted. 

We  have  thus  far  only  considered  the  agency  of 
the   aqueous   circulation   in  distributing  over  the 
earth  the  chief  constituent  of  all  organic  Agency  of 
matter,  together  with  some  of  the  second-  ™**r.  ia 

distributing 

ary  ends  which  the  river-system  of  the  heat- 


146  KELIGION   AND    CHEMISTRY.  [LECT.  V. 

globe  subserves.  But  there  is  another  condition  of 
organic  life  no  less  essential  than  moisture.  The 
animal  kingdom  is  absolutely  dependent  on  the  veg- 
etable, and  plants  cannot  grow  except  within  a  lim- 
ited range  of  temperature.  Therefore,  unless  dur- 
ing at  least  a  portion  of  the  year  the  amount  of  heat 
supplied  is  sufficient  to  maintain  the  temperature 
of  the  climate  within  the  required  limits,  organic 
life  cannot  exist  in  that  region.  Now  this  familiar 
substance,  water,  has  been  endowed  with  most  re- 
markable and  unusual  properties,  by  which  the 
aqueous  circulation  has  been  made  a  great  means 
of  distributing  heat,  and  thus  of  sustaining  organic 
life  in  vast  tracts  of  country  where  otherwise  it 
could  not  exist ;  and  it  is  to  this  class  of  its  adapta- 
tions that  I  wish  next  to  call  your  attention. 

One  of  the  prominent  inventions  of  modern  times 
is  the  method  of  heating  large  buildings  by  steam. 
Latent  heat  You  must  all  have  seen  the  apparatus. 
of  steam.  There  is  first  the  boiler,  where  the  steam 
is  generated  by  the  combustion  of  fuel ;  then  pipes, 
by  which  it  is  distributed  to  the  different  rooms; 
next  the  iron  radiators,  in  which  the  steam  is  con- 
densed to  water,  and  during  this  change  gives  out 
heat,  which  is  radiated  from  the  corrugated  surface 
of  the  iron ;  and,  lastly,  the  return  pipes,  through 
which  the  condensed  water  flows  back  to  the  boiler, 
ready  to  start  again  on  the  same  journey.  Every 
one  is  familiar  with  these  external  aspects  of  the 
apparatus ;  but  all  may  not  know  that  the  efficiency 
of  the  method  depends  entirely  upon  a  remarkable 


LECT.  V.]  TESTIMONY   OF   WATER.  147 

quality  of  water,  a  quality  which  is  not  ^possessed  to 
the  same  degree  by  any  other  known  liquid.  Were 
you  to  test  with  a  thermometer  the  temperature  of 
the  water  in  the  boiler  and  that  of  the  steam  rising 
from  it,  you  would  be  surprised  to  find, — if  you  were 
not  forewarned  of  the  fact, — that  they  were  both  at 
precisely  the  same  point ;  and  yet  in  order  to  change 
one  pound  of  boiling  water  into  one  pound  of  steam 
it  is  necessary  to  burn  up  sufficient  coal  to  raise  the 
temperature  of  ten  pounds  of  ice-cold  water  to  the 
boiling  point.  The  coal  which  is  burning  under  the 
boiler  does  not  raise  the  temperature  of  the  water. 
Press  the  fire  ever  so  hard,  you  cannot  increase  the 
temperature  either  of  the  water  or  of  the  steam  by  a 
single  degree.  The  effect  of  increasing  the  fire  will 
be  only  to  generate  steam  more  rapidly,  for  the 
whole  of  the  immense  amount  of  heat  set  free  by 
the  burning  fuel  is  absorbed  by  the  boiling  water  in 
changing  into  steam.  But  this  heat  is  not  lost.  It 
remains  latent  in  the  steam,  is  carried  by  it  into  the 
different  rooms,  and  there,  when  the  steam  changes 
back  again  into  water,  it  is  all  given  up,  without 
the  slightest  diminution,  diffusing  its  genial  warmth 
through  the  house.  The  steam,  therefore,  is  merely 
the  vehicle  by  which  heat  is  carried  over  the  build- 
ing. The  heat  comes  from  the  burning  fuel  in  the 
cellar,  and  originally  it  came  from  the  sun ;  for  the 
coals  burning  under  the  boiler  are  merely  fagots, 
as  it  were,  of  condensed  sunbeams,  gathered  by  the 
plants  of  some  ancient  geological  epoch,  subsequent- 
ly fossilized  and  preserved  in  the  earth  for  our  use 


148  RELIGION   AND    CHEMISTRY.  [LECT.  V. 

The  steam  -merely  acts  the  part  of  a  common  car- 
rier ;  but  what  I  wish  you  to  notice  is  the  fact  that 
steam  is  peculiarly  fitted  for  the  work,  because  it 
has  been  made  capable  of  holding  so  large  a  quan- 
tity of  heat. 

Your  attention  perhaps  has  been  called  to  the  ef- 
ficiency and  economy  of  this  method  of  heating, 
you  have  admired  its  neatness  and  absolute  safety 
from  fire,  and  have  been  delighted  with  the  softness 
of  the  temperature  which  it  diffuses  through  the 
rooms.  Or,  if  you  have  examined  more  closely  the 
details  of  the  apparatus,  you  must  have  been  struck 
with  the  ingenuity  of  tfye  adjustments  by  which  it 
is  self-regulated.  Yet  this  is  no  new  invention.  A 
similar  apparatus,  on  a  vastly  grander  scale,  working 
with  far  greater  economy  and  efficiency,  and  pro- 
vided with  adjustments  of  wonderful  delicacy,  which 
perfectly  regulate  its  action,  and  which  never  fail 
and  never  wear  out,  has  been  at  work  ever  since 
the  dawn  of  the  creation,  and  is  at  this  moment  soft- 
ening the  inclemency  of  our  Northern  winter. 

The  general  aqueous  circulation  is  a  great  steam- 
heating  apparatus,  with  its  boiler  in  the  tropics  and 
its  condensers  all  over  the  globe.  The  sun's  rays 
make  the  steam,  and  wherever  dew,  rain,  or  snow 
falls,  there  the  heat,  which  came  originally  from  the 
sun,  and  which  has  been  brought  from  the  tropics 
concealed  in  the  folds  of  the  vapor,  is  set  free  to 
warm  the  less  favored  regions  of  the  earth.  This 
apparatus  of  nature,  although  so  much  simpler,  and 
working  without  pipes,  iron  boiler,  or  radiators,  is 


LECT.  V.]  TESTIMONY    OF   WATER.  149 

exactly  the  same  in  principle  as  the  steam-heater, 
which  may  be  seen  at  work  in  almost  every  large 
factory.  It  is  true  that  the  atmospheric  vapor  is  a 
much  better  vehicle  of  heat  than  ordinary  steam,  and 
it  is  also  true  that  this  thermal  application  is  but 
one  of  the  hundred  uses  of  the  aqueous  circulation  ; 
but  still  the  general  method  is  the  same,  and  both 
systems  owe  their  efficiency  to  the  unique  proper- 
ty with  which  water  has  been  endowed.  It  is  true 
that  other  liquids  in  changing  into  vapor  absorb 
heat,  but  the  heat  stored  up  in  these  vapors  is  vast- 
ly less  than  that  in  steam,  and  it  must  be  noticed 
that,  of  all  created  forms  of  matter,  this  familiar 
liquid,  which  fills  the  ocean,  which  distils  upon  us 
in  the  rain,  and  which  flows  in  the  rivers,  is  the  only 
substance  which  has  been  thus  especially  endowed. 
Is  this  an  accidental  concurrence  of  circumstances  ? 
or  is  it,  on  the  contrary,  the  work  of  Infinite  Wis- 
dom ?  We  regard,  and  with  reason,  the  beautiful 
invention  of  man,  by  which  our  dwellings  are 
warmed,  as  an  evidence  of  intelligence ;  and  can  we 
refuse  to  recognize  the  existence  of  that  higher  In- 
telligence, which  not  only  adjusted  the  more  perfect 
system  of  nature,  but  also  created  the  properties 
of  water,  on  which  the  efficiency  of  both  depends  ? 
Having  considered  that  peculiar  quality  of  va- 
por through  which  the  aqueous  circulation  becomes 
an  important  means  of  distributing  the  sun's  heat 
over  the  surface  of  the  globe,  we  might  next  discuss 
more  at  length  the  extent  of  its  influence,  and  ex- 
amine in  detail  the  ingenious  system  of  checks  and 


150  RELIGION   AND    CHEMISTRY.  [!ECT.  V. 

balances  by  which  the  action  of  this  great  heating 
apparatus  is  regulated,  and  its  constant  working  se- 
cured ;  but  here,  as  before,  having  glanced  at  the 
main  points,  I  must  leave  it  to  your  study  to  fill  the 
unavoidable  blanks,  and  pass  on  to  consider  another 
special  property  of  water  by  which  a  similar  result 
is  secured. 

The  amount  of  heat  required  to  raise  the  tem- 
perature of  a  pound  of  water,  or  of  any  other 
capacity  of  substance,  one  degree,  is  capable  of  exact 
water  for  heat,  measurement,  and  the  quantity  has  been 
determined  experimentally  for  almost  every  known 
substance.  These  experiments  have  led  to  a  re- 
markable result,  to  which  I  alluded  in  a  former 
Lecture.  It  appears  that,  when  water  is  heated 
through  a  given  number  of  degrees,  it  absorbs 
more  than  twice  as  much  heat  as  any  other  sub- 
stance except  hydrogen  gas,  —  which  is  one  of  its 
constituent  elements,  —  and  more  than  ten  times 
as  much  as  iron  and  most  of  the  metals.  It  is  not 
probable  that  many  of  my  audience  have  verified 
this  striking  result,  but  you  all  know  how  long  it 
takes  to  boil  a  tea-kettle,  even  over  a  brisk  fire,  and 
have,  therefore,  some  conception  of  the  amount 
of  heat  which  cold  water  is  capable  of  absorbing. 
This  familiar  experience  shows  that  water  has  a 
very  great  capacity  of  holding  heat,  and  accurate 
experiment  has  proved,  as  just  stated,  that  at  the 
same  temperature  water  contains  more  than  twice 
as  much  heat  as  any  other  solid  or  liquid  known. 

The  importance  of  this  simple  provision  will  ap- 


LECT.  V.]  TESTIMONY   OF   WATER.  151 

pear,  if  you  reflect  that  it  makes  the  ponds,  the 
lakes,  and  the  oceans  great  reservoirs  of  heat.  It 
not  only  requires  a  vast  amount  of  heat  to  warm 
one  of  these  large  bodies  of  water,  but  when  once 
warmed  they  cool  very  slowly.  Hence  the  marked 
difference  between  the  oceanic  and  the  continental 
climate  in  the  same  latitude.  During  the  summer 
the  ocean  eagerly  absorbs  the  heat  of  the  sun's  rays, 
which  are  showered  upon  it  in  such  profusion ;  but 
water  has  so  great  a  capacity  for  heat,  that  the 
ocean,  nevertheless,  does  not  grow  very  warm, 
and,  moreover,  a  large  amount  of  the  heat  it  re- 
ceives is  carried  away  by  the  vapor  which  is  con- 
stantly rising  from  its  surface.  In  winter,  on  the 
other  hand,  the  water  gives  up  its  heat  to  warm 
the  colder  air ;  but  it  contains  such  an  inexhausti- 
ble supply,  that  the  loss  does  not  materially  lower 
its  temperature.  There  results  in  consequence  a 
great  uniformity  of  temperature,  in  which  the  air, 
by  its  perpetual  contact  with  the  surface  of  the 
water,  necessarily  shares,  and  this  uniformity  ex- 
tends, in  a  greater  or  less  degree,  to  the  climate 
of  all  islands  and  sea-board  districts.  It  is  quite 
different  with  the  surface  of  continents.  There 
the  soil  becomes  rapidly  heated  under  the  vertical 
rays  of  a  summer's  sun,  and,  as  its  particles  are 
immovable,  the  surface-layer  soon  rises  to  a  high 
temperature,  while,  on  the  other  hand,  in  winter  it 
is  cooled  by  radiation  with  equal  rapidity ;  and  this 
is  the  cause  of  those  extremes  of  heat  and  cold 
which  characterize  all  countries  of  the  temperate 


152  RELIGION   AND    CHEMISTRY.  [LECT.  V. 

zone  removed  from  the  influence  of  the  ocean. 
The  oceanic  climate  is  moderate,  while  the  conti- 
nental climate  is  excessive.  During  the  day,  under 
the  same  circumstances,  the  land  is  warmer  than 
the  sea,  and  colder  during  the  night,  or,  taking  the 
different  seasons,  the  land  is  warmer  than  the  sea  in 
summer  and  colder  in  winter*  These  general  prin- 
ciples have  been  verified  by  the  extensive  series  of 
meteorological  observations  which,  during  the  last 
twenty-five  years,  have  been  made  all  over  the  civ- 
ilized world.  You  will  find  an  excellent  abstract 
of  the  results  in  Professor  Guyot's  work  on  "  Earth 
and  Man,"  before  referred  to.  I  have  time  only  to 
cite  a  few  familiar  facts  in  illustration  of  my  sub- 
ject, which  I  will  give  nearly  in  his  words. 

"On  the  coast  of  Cornwall  shrubs  as  delicate  as 
the  laurel  or  the  camellia  are  green  through  the 
whole  year,  while  under  the  same  latitude  in  the 
interior  of  the  continents,  the  most  hardy  trees  can 
alone  brave  the  rigor  of  the  winter.  But  on  the 
other  hand,  the  mild  climate  of  England  cannot 
ripen  the  grape,  although  almost  under  the  same 
parallel  grow  the  delicious  wines  of  the  Rhine.  At 
Astrachan,  on  the  northern  shore  of  the  Caspian,  as 
Humboldt  tells  us,  the  grapes  and  fruits  of  every 
kind  are  as  beautiful  and  luscious  as  in  the  Cana- 
ries and  in  Italy;  the  wines  have  all  the  fire  of 
those  of  the  South  of  Europe,  although  in  the  same 
latitude,  at  the  mouth  of  the  Loire,  on  the  Atlantic 
sea-coast,  the  vines  hardly  flourish  at  all.  But  while 
in  the  South  of  France  the  winter  is  a  perpetual 


LECT.  V.]  TESTIMONY   OF   WATER.  153 

spring,  the  summers  of  the  Caspian  are  succeeded 
by  a  winter  of  almost  polar  severity." 

I  might  multiply  illustrations,  but  these  are  suf- 
ficient to  show  how  the  remarkable  property  of 
water  which  we  are  considering  tends  to  equalize 
the  climate  of  the  globe. 

This  influence  of  water  is  very  greatly  increased 
by  the  oceanic  currents,  which,  like  the  winds,  are 
set  in  motion  by  the  heat  of  the  sun,  and  Oceanic 
are  constantly  carrying  the  warm  waters  currents- 
of  the  tropics  toward  the  poles.  One  of  the  most 
remarkable  of  these  currents  is  the  Gulf-Stream, 
which  flows  near  our  coast,  and  which  diffuses  the 
warm  waters  of  the  Caribbean  Sea  and  the  Gulf 
of  Mexico  over  the  Northern  Atlantic,  deposit- 
ing on  the  shores  of  Scotland  and  Norway  the 
plants  and  seeds  of  the  tropics.  It  is  solely  the 
heat  which  these  waters  bring  with  them  from  the 
equator  that  has  made  the  island  of  Great  Britain 
so  great  a  centre  of  commerce  and  civilization ;  for 
it  must  be  remembered  that  the  latitude  of  Eng- 
land is  the  same  as  that  of  Labrador,  and,  were  it 
not  for  the  influence  of  this  ocean  current,  her  soil 
would  be  equally  desolate  and  barren.  If  the  con- 
figuration of  our  Western  Continent  were  only  so 
slightly  changed  as  to  give  a  passage  to  the  great 
equatorial  current  through  the  present  Isthmus  of 
Panama,  a  change  insignificant  in  comparison  with 
those  which  have  heretofore  taken  place,  "the 
mountains  of  Wales  and  Scotland  would  become 
again  the  abode  of  glaciers,  and  civilization  would 


154  KELIGION   AND    CHEMISTRY.  [LECT.  V. 

disappear  before  the  invasion  of  arctic  cold."  *  So 
also  it  is  to  the  enormous  mass  of  heated  water 
which  the  Gulf-Stream  pours  into  the  seas  sur- 
rounding Northern  Europe  that  Sweden  and  Nor- 
way owe  their  temperate  climate,  while  at  the  cor- 
responding latitudes  on  our  own  continent  the  land 
is  shrouded  in  eternal  ice  and  snow. 

But,  my  friends,  all  these  provisions  for  dis- 
tributing heat  over  the  earth's  surface  would  have 
point  of  maxi-  been  insufficient  to  maintain  organic  life 
mum  density.  *n  our  Northern  climate,  were  it  not  for 
still  another  remarkable  property  with  which  water 
has  been  endowed,  —  a  property  even  more  entirely 
unique  than  either  of  those  we  have  studied,  and 
one  which  seems  to  be  an  exception  to  the  general 
laws  of  nature.  The  familiar  cycles  of  organic  life, 
both  in  animals,,  and  plants,  are  intimately  associ- 
ated with  the  succession  of  the  seasons,  and  this  in 
its  turn  depends  on  the  inclination  of  the  earth's 
axis  to  the  plane  of  the  ecliptic,  and  on  the  great 
primary  laws  by  which  this  axis  is  constantly  main- 
tained in  a  position  parallel  to  itself  during  the 
revolution  of  the  planet  around  the  sun.  To  these 
fundamental  conditions  in  the  formation  of  the  solar 
system  the  whole  constitution  of  organic  life  on  the 
earth  has  been  adjusted ;  and  Professor  Whewell, 
in  his  excellent  Bridgewater  Treatise,  has  discussed 
at  length  the  evidences  of  design  which  this  cir- 
cumstance affords.  It  would  be  foreign,  however, 

*  W.  Hopkins's  Address  before  the  Geological   Society  of  Great 
Britain. 


LECT.  V.]  TESTIMONY   OF   WATER.  155 

to  my  plan,  to  consider  these  evidences  here ;  but, 
assuming  the  succession  of  the  seasons  as  a  part  of 
the  order  of  creation,  and  as  a  means  of  adapting  a 
larger  portion  of  the  earth's  surface  for  the  habita- 
tion of  organized  beings,  it  is  evident  that  the 
higher  forms  of  organic  life  could  be  sustained  in 
these  Northern  regions  only  by  furnishing  to  the 
plants  and  animals  an  adequate  protection  against 
the  intense  cold  of  winter,  and  thus  preserving 
the  growth  of  one  summer  until  the  returning 
sun  awakens  new  life  in  the  succeeding  spring. 

The  required  protection  has  been  provided  by 
making  a  most  marked  exception  to  the  general 
laws  of  expansion  in  the  case  of  water.  It  is  the 
general  law  of  nature,  that  all  substances  are  ex- 
panded by  heat  and  contracted  by  cold,  and  water 
forms  no  exception  to  the  general  rule,  except 
within  certain  very  narrow  limits  of  temperature, 
shortly  to  be  noticed.  Indeed,  were  it  not  for 
the  expansion,  we  could  not  readily  either  heat  or 
cool  a  large  mass  of  liquid  matter.  All  liquids  are 
very  poor  conductors  of  heat,  and  can  be  heated 
only  by  bringing  their  particles  successively  in  con- 
tact with  the  source  of  heat.  When  you  set  a 
tea-kettle  over  a  fire,  the  first  effect  of  the  heat 
is  to  expand  the  particles  of  water  resting  on  the 
bottom  of  the  kettle,  which,  being  thus  rendered 
specifically  lighter,  rise,  and  are  succeeded  by  colder 
particles,  which  are  heated  and  rise  in  their  turn ; 
and  thus  a  circulation  is  established  by  which  all 
the  particles  are  successively  brought  in  contact 


156  RELIGION   AND    CHEMISTRY.  [LECT.  V. 

with  the  heated  bottom  of  the  kettle,  and  in  the 
course  of  time  the  temperature  of  the  whole  mass 
is  raised  to  the  boiling  point.  The  case  is  similar 
when  you  add  ice  to  a  pitcher  of  water  in  order  to 
cool  it.  The  water  at  the  top  of  the  pitcher,  in 
contact  with  the  ice,  is  of  course  cooled,  and,  being 
thus  rendered  specifically  heavier  than  the  water 
below,  sinks  and  gives  place  to  the  warmer  water, 
which  is  cooled  and  sinks  in  its  turn,  and  thus  as 
before  a  circulation  is  established,  which  continues 
until  the  temperature  of  the  whole  water  is  re- 
duced to  40°.  But  at  this  point  the  circulation  is 
entirely  arrested ;  for,  in  consequence  of  its  singu- 
lar constitution,  water  at  39°  is  lighter  than  water 
at  40°,  and  consequently  remains  at  the  top.  And 
so  it  is  as  the  temperature  sinks  toward  the  freez- 
ing point.  The  colder  the  water,  the  lighter  it 
becomes,  and  the  more  persistently  it  remains  at 
the  surface.  Hence,  although  the  upper  layers  of 
water  may  be  readily  cooled  to  the  freezing  point, 
yet,  in  consequence  of  its  poor  conducting  power, 
the  great  body  of  the  liquid  below  will  remain  at 
the  temperature  of  40°. 

The  cold  atmosphere  of  winter  acts  upon  the 
ponds  and  lakes  exactly  as  the  ice  on  the  water  in 
the  pitcher.  They  also  are  cooled  from  the  sur- 
face, and  a  circulation  is  established  by  the  con- 
stant sinking  of  the  chilled  water  until  the  tem- 
perature falls  to  40°.  But  at  this  point,  still  eight 
degrees  above  the  freezing  point,  the  circulation 
stops.  The  surface-water,  as  it  cools  below  this 


LECT.  V.]  TESTIMONY   OF   WATER.  157 

temperature,  remains  at  the  top,  and  in  the  end 
freezes  ;  but  then  comes  into  play  still  another  pro- 
vision in  the  properties  of  water.  Most  substances 
are  heavier  in  their  solid  than  in  their  liquid  state, 
but  ice,  on  the  contrary,  is  lighter  than  iceiighter 
water,  and  therefore  floats  on  its  surface.  thanwater- 
Moreover,  as  ice  is  a  very  poor  conductor  of  heat, 
it  serves  as  a  protection  to  the  lake,  so  that  at  the 
depth  of  a  few  feet,  at  most,  the  temperature  of  the 
t  water  during  winter  is  never  under  40°,  although 
the  atmosphere  may  continue  for  weeks  below  zero. 
If  water  resembled  other  liquids,  and  continued 
to  contract  with  cold  to  its  freezing  point,  —  if  this 
exception  had  not  been  made,  the  whole  order  of 
nature  would  have  been  reversed.  The  circulation 
just  described  would  continue  until  the  whole  mass 
of  water  in  the  lake  had  fallen  to  the  freezing  point. 
The  ice  would  then  first  form  at  the  bottom,  and 
the  congelation  would  continue  until  the  whole 
lake  had  been  changed  into  one  mass  of  solid  ice. 
Upon  such  a  mass  the  hottest  summer  would  pro- 
duce but  little  effect ;  for  the  poor  conducting 
power  would  then  prevent  its  melting,  and  instead 
of  ponds  and  lakes  we  should  have  large  masses  of 
ice,  which  during  the  summer  would  melt  on  the 
surface  to  the  depth  of  only  a  few  feet.  It  is  un- 
necessary to  state  that  this  condition  of  things 
would  be  utterly  inconsistent  with  the  existence  of 
aquatic  plants  or  animals,  and  it  would  be  almost 
as  fatal  to  organic  life  everywhere ;  for  not  only 
are  all  parts  of  the  creation  so  indissolubly  bound 


158  RELIGION   AND    CHEMISTRY.  [LECT.  V. 

together  that,  if  one  member  suffers,  all  the  other 
members  suffer  with  it,  but  moreover  the  soil  itself 
would,  to  a  certain  extent,  share  in  the  fate  of  the 
ponds.  The  soil  is  always  more  or  less  saturated 
with  water,  and,  under  existing  conditions  in  our 
temperate  zone,  the  frost  does  not  penetrate  to 
a  sufficient  depth  to  kill  the  roots  and  seeds  of 
plants  which  are  buried  under  it.  But  were  water 
constituted  like  other  liquids,  the  soil  would  remain 
frozen  to  the  depth  of  many  feet,  and  the  only  ef- 
fect of  the  summer's  heat  would  be  to  melt  a  few 
inches  at  the  surface.  It  would  be,  perhaps,  possi- 
ble to  cultivate  some  hardy  annuals  in  such  a  cli- 
mate, but  this  would  be  all.  Trees  and  shrubs 
could  not  brave  the  severity  of  the  winter.  Thus, 
then,  it  appears  that  the  very  existence  of  life  in 
these  temperate  regions  of  the  earth  depends  on  an 
apparent  exception  to  a  general  law  of  nature,  so 
slight  and  limited  in  its  extent  that  it  can  only 
be  detected  by  the  most  refined  scientific  obser- 
vation. 

Moreover,  this  exceptional  property  is  united  in 
water  with  another  quality,  which  greatly  aids  in 

preserving  vegetable  life  during  the  win- 
conductor  ter  months.  We  shudder  at  the  thought 

of  snow,  but  nevertheless  it  affords  a  most 
effectual  protection  to  the  soil,  forming  as  warm  a 
covering  as  would  the  softest  wool.  Water  in  all 
its  conditions  has  been  made  a  very  bad  conduc- 
tor of  heat,  and  snow  is  ranked  with  wool  among 
the  poorest  of  conductors.  Heat,  therefore,  cannot 


LECT.  V.]  TESTIMONY   OF   WATER.  159 

readily  escape  from  a  snow-covered  soil,  and  thus 
its  temperature  is  prevented  from  falling  materially 
below  the  freezing  point,  however  great  the  severity 
of  the  season.  Notice  now  how,  when  winter  sets 
in  and  the  cold  increases  to  such  a  degree  as  to  en- 
danger the  tender  plants,  Nature  promptly  spreads 
her  great  frost-blanket  over  forest,  prairie,  meadow, 
and  garden  alike,  so  that  all  may  slumber  on  in 
safety  until  the  sun  returns  and  melts  away  the 
downy  covering,  when  the  buds  break  forth  again  S 
and  the  trees  put  on  a  new  mantle  of  living  green. 
This  leads  me  to  speak  of  still  another  remark- 
able property  of  the  wonderful  liquid  we  are  study- 
ing :  for  nature  has  provided  in  the  consti- 

.  Heat  of  fusion. 

tution  of  water  a  most  effectual  means  of 
tempering  the  transition  of  the  seasons,  and  protect- 
ing vegetation  against  the  early  frosts  of  autumn 
or  the  first  deceptive  glow  of  returning  spring.  In 
order  to  freeze  a  liquid  it  is  necessary  to  remove 
from  it  a  certain  quantity  of  heat  called  the  heat  of 
fusion,  and  the  more  of  this  heat  a  liquid  contains, 
with  the  more  difficulty  of  course  it  freezes,  and 
when  once  frozen  the  less  readily  the  solid  melts. 
Now  water  contains  a  larger  amount  of  heat  of  fu- 
sion than  any  other  liquid  yet  examined,  and  in 
this  respect,  therefore,  it  is  also  peculiarly  consti- 
tuted. And  mark  how  this  property  tends  to  pro- 
duce the  result  just  noticed.  As  the  weather  be- 
comes cooler  in  autumn,  our  ponds  and  lakes  grad- 
ually give  up  the  stores  of  heat  which  they  contain, 

until  the  temperature  of  the  whole  mass  of  water  is 
11 


160  RELIGION   AND    CHEMISTRY.  [LECT.  V. 

reduced  to  40° ;  then  the  surface-water  cools  still 
further  to  the  freezing  point ;  but  before  it  can  be- 
come any  colder  than  this  the  water  must  freeze, 
and  in  freezing  it  will  set  free  four  times  as  much 
heat  as  it  has  already  given  out  in  cooling  from  the 
temperature  of  summer  (63°)  to  the  freezing  point. 
It  is  evident,  therefore,  that  freezing  must  be  a  slow 
process.  Moreover,  it  is  also  a  warming  process, 
and  although  the  temperature  of  surrounding  ob- 
jects can  never  be  thus  raised  above  the  freezing 
point,  nevertheless,  the  immense  amount  of  heat 
evolved  greatly  tends  to  retard  the  approach  of  se- 
vere cold,  and  prepares  the  way  for  the  inclemency 
of  winter.  So  also,  when  Spring  comes,  vegetation 
is  not  awakened  by  her  first  blushes  to  be  exposed 
to  the  blights  of  the  early  frosts,  and  before  the 
snow  covering  can  be  melted  off  the  danger  is 
mostly  passed.  Again,  when  we  consider  what  de- 
yastating  floods  would  sweep  the  earth  were  the  icy 
bonds  of  winter  suddenly  dissolved,  we  shall  dis- 
cover still  further  evidence  of  the  wisdom  of  that 
Being  who  has  so  adjusted  the  properties  of  water 
that  both  frost  and  freshet  are  the  exception,  not 
the  rule. 

I  have  said  that  water  presents  the  only  well- 
established  exception  to  the  laws  of  expansion  by 
heat,  and  some  writers  on  natural  theology  have 
dwelt  on  this  point  as  one  of  great  importance  to 
their  argument.  But  I  cannot  think  they  are 
wise ;  for,  to  say  the  least,  they  rest  their  argument 
on  our  ignorance  and  not  on  our  knowledge.  It  is 


LECT.  V.]  TESTIMONY   OF   WATER.  161 

true  that  in  the  present  state  of  science  the  anom- 
alous expansion  of  water  near  the  freezing  point 
seems  to  be  an  exception  to  the  general  laws  of 
nature;  but  hereafter  this  very  anomaly  may  ap- 
pear to  be  the  natural  result  of  a  more  general 
law  not  yet  discovered,  or,  like  the  perturbations 
in  the  orbits  of  the  planets,  may  prove  to  be 
the  strongest  confirmation  of  the  very  law  it  now 
seems  to  invalidate.  Moreover,  I  do  not  share  in 
that  indefinite  dread  of  natural  laws  which  troubles 
so  many  religious  minds.  To  me  the  laws  of  nature 
afford  the  strongest  evidences  of  the  existence  of  a 
God,  and  in  their  uniformity  I  see  merely  the  con- 
stant action  of  an  omnipresent  Creator,  who  acts 
with  perfect  regularity  because  he  acts  consistently 
and  with  infinite  wisdom.  I  believe  that  all  parts 
of  nature  are  correlated  by  laws,  and  that  the  wider 
our  knowledge  becomes,  the  more  universal  these 
laws  will  appear.  I  do  not,  therefore,  regard  the 
constitution  of  water  as  something  apart  from  law, 
and  as  the  evidence  of  a  power  coming  down  as  it 
were  upon  law  to  make  an  exception  to  it.  This  is 
making  altogether  too  much  of  law.  God  is  not 
bound  by  law.  He  acts  wisely,  beneficently,  and 
with  a  definite  plan,  and  the  most  we  can  claim  for 
natural  laws  is,  that  they  are  our  imperfect  human 
expressions  of  this  Divine  plan.  Moreover,  that  is 
a  far  nobler  view  of  God's  wisdom  which  supposes 
him  to  be  able  to  harmonize  special  adaptations 
with  general  laws.  What  I  find  so  remarkable  in 
the  constitution  of  water  is,  not  that  it  is  an  excep- 


162  RELIGION   AND    CHEMISTRY.  [LECT.  V. 

tion  to  the  general  laws  of  nature,  but  that,  while 
filling  its  place  in  the  general  plan,  it  has  been  en- 
dowed with  such  extreme  properties,  and  that  in 
each  case  the  peculiar  property  has  special  adapta- 
tions at  once  so  complex  and  so  important.  Not 
only  has  water  this  exceptional  property  of  expand- 
ing when  other  liquids  contract,  but  moreover,  of 
all  known  substances,  it  has  the  greatest  capacity 
for  heat;  so  also,  when  changing  into  vapor,  it  ab- 
sorbs more  heat  than  any  other  liquid ;  again,  it 
is  far  lighter  in  the  solid  than  in  the  liquid  state ; 
and  lastly,  it  contains  the  largest  amount  of  heat 
of  fusion  as  yet  observed  in  any  substance.  All 
this  may  be  in  harmony  with  general  laws.  I  have 
no  doubt  that  it  is ;  but  the  existence  of  the  law 
does  not  in  the  least  impair  the  significance  of 
the  fact,  that  in  each  of  these  respects  water  has 
been  peculiarly  constituted.  This  one  liquid  of 
the  globe,  which  covers  more  than  three  fourths 
of  its  surface,  which  circulates  through  all  its  chan- 
nels, which  percolates  through  all  its  pores,  which 
constitutes  three  fourths  of  all  organized  beings, 
has  been  endowed  with  these  four  pre-eminent 
qualities,  on  each  of  which  the  whole  order  of 
terrestrial  nature  may  be  said  to  depend.  I  can- 
not conceive  of  stronger  evidence  of  design  than 
this ;  and  if  these  facts  do  not  prove  the  existence 
of  an  intelligent  Creator,  then  all  nature  is  a  de- 
ception and  our  own  faculties  a  lie.  Yet,  my 
friends,  this  is  only  a  small  part  of  the  evidence 
of  design  which  science  has  discovered  in  this  fa- 


LECT.  V.]  TESTIMONY   OF   WATER.  163 

miliar  liquid.  I  might  occupy  several  Lectures 
with  this  subject  alone,  but  I  have  time  only  to 
glance  at  two  more  striking  facts. 

Water  is  the  most  universal  solvent  known,  and 
there  are  but  few  substances  which  are  not  to  a 
greater  or  less  degree  dissolved  by  it.  Soivent  power 
Those  which  we  call  insoluble  generally  ofwater- 
differ  from  the  rest  only  in  degree.  Thus,  all  lime 
rocks  dissolve  to  a  limited  extent  in  spring  water, 
and  the  same  is  also  true  of  almost  all  mineral  sub- 
stances. The  magnificent  crystals  which  we  fre- 
quently find  in  the  rocks  are  formed  in  almost  ev- 
ery case  by  a  deposition  of  the  mineral  substance 
from  a  state  of  solution  in  water.  The  feeble  sol- 
vent power  of  the  water  for  these  substances  is 
made  up  by  the  large  volume  of  the  solution,  and 
the  length  of  time  occupied  in  the  process  of  crystal- 
lization. Many  of  the  large  crystals  which  may  be 
seen  in  cabinets  of  minerals  have  been  unquestiona- 
bly thousands  of  years  in  formation.  And  not  only 
does  the  solvent  power  of  water  stud  the  cavities 
of  the  rocks  with  gems,  but  it  is  also  constantly 
producing  most  important  changes  in  the  rocky 
structures  of  the  globe  itself,  here  cementing  to- 
gether the  loose  sands,  and  there  converting  the 
soft  clays  into  firm  and  solid  rock. 

Again,  the  solvent  power  of  water  extends  to 
aeriform  as  well  as  to  solid  substances,  so  that  the 
gases  composing  the  air  pervade  the  lakes  and  the 
oceans  as  well  as  the  atmosphere.  Indeed,  it  is  on 
the  gases  dissolved  in  the  water  that  all  the  aquatic 


164  RELIGION   AND    CHEMISTRY.  [LECT.  V. 

plants  and  animals  live,  and  the  members  of  the 
various  finny  tribes  breathe  the  free  oxygen  dis- 
solved in  the  water,  as  we  breathe  the  oxygen  of 
the  air.  Again,  the  process  of  respiration  is  es- 
sentially the  same  with  these  lower  animals  that  it 
is  with  us,  and  the  structure  of  their  organs  has 
been  adjusted  to  the  amount  of  this  life-sustaining 
element,  which  water  is  capable  of  dissolving. 
Moreover,  the  power  which  water  possesses  of  dis- 
solving oxygen  is  much  greater  than  its  power  of 
dissolving  nitrogen,  and  hence  the  air  dissolved  in 
the  ocean  is  proportionally  much  richer  in  oxygen 
than  our  atmosphere.  This  is  undoubtedly  anoth- 
er quality  with  which  water  has  been  endowed  in 
order  to  render  the  oceans,  the  lakes,  and  the 
rivers  a  fit  habitation  for  that  world  of  organic 
life  which  modern  zoology  has  revealed.  That  we 
are  unable  to  trace  all  its  relations,  is  evidently 
owing  to  the  imperfection  of  our  knowledge.  But 
here  a  new  field  of  study  opens  before  us,  which, 
when  fully  explored,  will  undoubtedly  prove  as  rich 
in  the  evidence  of  design  as  the  atmosphere  itself. 

It  is  not,  however,  merely  as  a  solvent,  that 
water  is  an  important  agent  in  the  great  labora- 
tory  of  the  world.  I  have  already  stated 
fo  w^^  ^n  extent  all  animal  and  vegeta- 
ble substances  are  composed  of  water,  and  that 
some,  such  as  the  jelly-fishes  among  animals,  and 
the  gourd  family  among  plants,  may  be  said  to  be 
living  forms  of  water.  But  we  should  entertain  a 
very  erroneous  conception  of  the  condition  of  the 


LECT.  V.]  TESTIMONY   OF   WATER.  165 

water  in  these  animal  and  vegetable  structures, 
were  we  to  regard  it  as  so  much  dead  material, 
building  up  the  form  like  the  bricks  in  an  edifice. 
This  water  is  in  constant  circulation,  conveying 
nourishment  to  all  the  parts,  and  at  the  same 
time  removing  from  the  system  those  tissues  which 
have  fulfilled  their  functions  and  become  effete. 
It  is  being  constantly  decomposed,  and  as  rap- 
idly again  reformed,  assuming  the  most  protean 
conditions,  and  administering  to  the  functions  of 
the  animal  economy  in  a  thousand  ways. 

As  a  constituent  of  inorganic  matter,  water  is  no 
less  important  than  it  is  in  organized  being.  A  sub- 
stance so  bland  as  water,  and  apparently  so  entirely 
inactive,  which  fills  the  most  delicate  vegetable 
cells,  and  penetrates  the  finest  capillaries  of  the 
body, — whose  minuteness  and  delicacy  no  art  can 
approach,  nor  imagination  scarcely  conceive, — yet 
without  affecting  either  in  the  slightest  degree,  we 
should  suppose  would  be  endowed  with  no  affini- 
ties, and  capable  of  exerting  no  chemical  force. 
Yet  what  is  the  fact  ?  In  attempting  to  classify 
chemical  compounds,  I  have  studied  with  care  the 
chemical  history  of  water,  and  its  relations  to  other 
substances,  and  it  is  still  to  me  a  perfect  enigma  in 
nature.  For,  so  far  from  being  that  inert  material 
which  its  bland  exterior  would  seem  to  indicate,  it 
is  among  the  most  important  of  chemical  agents, 
forming  some  of  the  most  stable  compounds,  and 
surprising  the  chemist  by  the  strength  of  its  affini- 
ties. Not  only  is  water  a  common  constituent  of 


166  RELIGION   AND    CHEMISTRY.  [LECT.  V. 

most  crystalline  salts,  and  an  essential  ingredient 
of  many  of  the  powerful  acids  which  are  used  both 
in  the  arts  and  in  the  chemist's  laboratory,  but  it 
makes  also  a  not  unimportant  part  of  the  rocky 
crust  of  the  globe.  Besides  forming  the  immense 
deposits  of  ice  which  perpetually  surround  either 
pole,  and  the  glaciers  which  creep  down  the  high 
mountain  slopes,  we  find  that  water  enters  as  an 
essential  ingredient  into  the  composition  of  talcose 
and  chlorite  slate,  gypsum,  serpentine,  soapstone, 
and  other  rocks.  Moreover,  water  is  the  medium 
in  which  most  chemical  processes  take  place,  and 
throughout  all  geological  history  it  has  been  pro- 
ducing the  most  fundamental  changes  in  the  com- 
position of  the  earth's  crust,  the  extent  of  which 
geologists  are  only  of  late  beginning  to  appre- 
ciate. It  is  now  supposed  that  granite  and  simi- 
lar rocks,  which  were  formerly  regarded  as  pro- 
ducts of  igneous  fusion,  have  been  really  formed 
from  loose  beds  of  mud  and  clay,  through  the 
transforming  power  of  this  wonderful  and  power- 
ful agent. 

When,  lastly,  we  consider  the  composition  of 
water,  our  wonder  is  still  further  increased ;  for 
composition  it  consists  of  two  permanent  gases,  con- 
of  water.  denscd  by  the  force  of  chemical  affinity 
to  the  liquid  condition.  With  one  of  these,  oxy- 
gen, you  are  already  familiar.  The  other  is  a 
light,  combustible  gas,  called  hydrogen,  fourteen 
and  a  half  times  lighter  than  air,  and  by  far  the 
lightest  form  of  matter  known.  One  cubic  foot  of 


LECT.  V.]  TESTIMONY   OF   WATER.  167 

water  yields  more  than  eighteen  hundred  cubic  feet 
of  a  mixture  of  these  two  gases,  and  so  persistently 
do  they  retain  their  aeriform  condition,  that  not 
even  a  pressure  of  twenty  tons  on  the  square  inch 
is  sufficient  to  reduce  them  to  liquids.  Yet,  im- 
mense as  this  pressure  seems,  requiring  all  the 
mechanical  skill  of  man  to  apply  it,  that  force  must 
be  still  greater  which  is  constantly  acting  in  every 
drop  of  water  to  hold  these  highly  elastic  gases 
in  the  liquid  state.  It  is  difficult  to  estimate  the 
magnitude  of  such  power,  as  our  only  standard  of 
measurement  is  the  quantity  of  some  other  force, 
equally  immeasurable,  which  is  required  to  balance 
the  first.  "Water  is  easily  decomposed  by  electrici- 
ty, and  the  amount  of  this  agent  required  to  force 
apart  its  constituents  may  perhaps  give  you  some 
imperfect  conception  of  the  magnitude  of  that 
power  by  which  they  are  so  securely  imprisoned. 
The  statement  may  seem  incredible,  but  yet  it 
has  been  proved  by  Professor  Faraday,  that  it 
requires  more  electricity  to  decompose  a  drop  of 
water  than  to  charge  a  thunder-cloud. 

What  a  revelation  of  power  we  have  here !  In 
every  drop  of  water  there  is  a  constant  striving  of 
the  elements  to  escape ;  they  are  exerting  a  force 
to  break  the  bonds  that  unite  them,  which  can 
be  measured  only  by  the  power  of  concentrated 
thunderbolts,  and  yet  this  immense  force  is  kept  in 
check  by  a  force  of  equal  power,  and  so  exactly 
balanced  that  not  the  slightest  disturbance  can  oc- 
cur. When,  now,  I  reflect  that  this  chemical  force 


168  RELIGION   AND    CHEMISTRY.  [LECT.  V. 

has  produced  a  result  which  all  human  strength, 
aided  by  the  appliances  of  modern  art,  has  been 
unable  to  effect,  —  that  in  every  particle  of  water 
the  force  is  still  acting,  so  that  every  rain-drop 
which  falls,  animates  the  river,  or  swells  the  ocean, 
is  a  silent  monitor  of  human  weakness,  I  am  over- 
whelmed by  that  mystery  in  nature,  which  here  as 
elsewhere  ever  points  upward  to  the  Infinite,  and 
thus  silently  teaches  that  the  mighty  influence 
which  binds  the  atoms  of  the  rain-drop  is  merely 
the  manifestation  of  His  ceaseless  power  who  hold- 
eth  "  the  waters  in  the  hollow  of  His  hand." 

It  is  a  very  common  mistake  to  suppose  that  the 
grand  in  nature  is  to  be  seen  only  in  its  great 
water-falls  and  its  lofty  mountains,  and  that,  in  or- 
der to  appreciate  the  omnipotence  of  the  Creator, 
we  must  cross  oceans  and  explore  continents ;  for, 
to  the  intellectual  eye,  there  is  more  evidence  of 
omnipotence,  more  real  grandeur,  in  a  single  rain- 
drop, than  in  the  roar  of  Niagara  or  in  the  magni- 
tude of  Mont  Blanc.  The  more  I  study  the  evi- 
dence of  design  in  this  simple  liquid,  the  more  I 
find  there  is  to  learn,  and  I  feel  the  utter  inade- 
quacy of  any  language  to  convey  the  full  and  com- 
plete idea.  Eeview  for  a  moment  the  examples 
of  adaptation  which  have  been  so  briefly  noticed. 
Kemember  that  water  is  the  liquid  of  our  globe, 
and  the  only  liquid  which  exists  in  any  abundance 
on  its  surface.  The  total  amount  of  all  other 
liquids  is  in  comparison  but  as  "a  drop  of  a 
bucket."  Consider,  next,  that  its  specific  gravity 


LECT.  V.]  TESTIMONY   OF  WATER.  169 

has  been  so  adjusted  that  our  ships  float,  and  the 
oceans  are  made  great  highways  for  the  nations; 
that  it  is  easily  converted  into  vapor,  and  as  easily 
condensed  to  fertilizing  rain  and  refreshing  dew, 
which  nourish  the  growing  plants,  fill  the  springs, 
and  keep  the  rivers,  the  great  arteries  of  the 
globe,  in  circulation;  that  at  a  comparatively  low 
temperature  it  is  changed  into  highly  elastic  steam, 
which,  imprisoned  by  man  in  his  iron  boilers,  has 
become  the  great  civilizer  of  the  world ;  that  it 
has  been  so  exceptionally  constituted  that  the  great 
mass  cannot  be  cooled  below  forty  degrees,  and 
again  has  been  made  such  a  poor  conductor  of 
heat  that,  when  the  surface  is  frozen,  the  very 
ice  becomes  a  protection  against  the  cold ;  that  to 
this  same  liquid  there  has  been  given  a  very  great 
capacity  for  heat,  and  that  thus  it  has  been  made 
the  means  of  tempering  materially  the  climates  of 
the  globe.  Add  to  this,  that  water  has  been  made 
an  almost  universal  solvent;  that  from  the  sub- 
stances it  holds  in  solution  the  Crustacea  form  their 
shells  and  the  coral  polypi  build  their  reefs ;  that 
it  fills  the  cavities  of  the  rocks  with  gems,  and  their 
fissures  with  useful  ores.  Besides  this  host  of  won- 
derful mechanical  adaptations,  remember  that  water 
has  been  made  a  chemical  agent  of  great  energy 
and  power ;  that  there  have  been  united  in  it  the 
apparently  incompatible  qualities  of  blandness  and 
great  chemical  force ;  that,  although  in  the  labora- 
tory of  nature  it  corrodes  the  most  resisting  rocks, 
it  also  circulates  through  the  leaflets  of  the  rose 


170  RELIGION  AND    CHEMISTRY.  [Lscx.  V. 

and  the  still  more  delicate  human  lungs;  that  it 
forms  the  greater  part  of  all  organized  beings,  from 
the  lichen  to  the  oak,  and  from  the  polyp  to  man. 
Keflect,  now,  that  these  are  only  a  few  of  the 
grosser  qualities  and  functions  of  this  remarkable 
compound,  gleaned  here  and  there  from  many 
others  no  less  wonderful,  and  you  will  form  still 
but  a  very  imperfect  conception  of  the  amount  of 
design  which  has  been  crowded  into  it.  Attempt 
to  find  a  liquid,  which,  if  in  sufficient  quantity, 
might  supply  its  place,  and  you  will  be  still  further 
impressed  by  this  evidence  of  intelligence  and  of 
thought.  Of  all  the  materials  of  our  globe,  water 
bears  most  conspicuously  the  stamp  of  the  Great 
Designer,  and  as  in  the  Book  of  Nature  it  teaches 
the  most  impressive  lesson  of  His  wisdom  and 
power,  so  in  the  Book  of  Grace  it  has  been  made 
a  token  of  God's  eternal  covenant  with  man,  and 
still  reflects  His  never-fading  promise  from  the 
painted  bow. 


LECTUKE    VI. 

TESTIMONY   OF   CARBONIC   ACID. 

WHEN  standing  by  some  quiet  mill-stream,  have 
you  ever  speculated  on  the  origin  of  the  power 
which  is  animating  the  machinery  of  that  great  fac- 
tory on  its  banks,  spinning  and  weaving  the  crude 
cotton  into  miles  of  cloth  every  week?  And  if, 
perchance,  you  have  visited  Niagara,  did  the  thought 
strike  you,  when  gazing  up  at  those  floods  of 
water,  which  came  tumbling  over  the  rocky  cliffs, 
and  plunging  into  the  seething  sea  at  your  feet, 
that  similar  floods  had  been  pouring  over  that 
ancient  river-bed  for  countless  ages,  yet  without 
diminishing  the  inexhaustible  supply  ?  Or,  if  it 
has  been  at  once  your  privilege  and  your  terror  to 
witness  that  grandest  sight  of  nature,  a  violent 
storm  at  sea,  have  you  been  impressed  by  the 
untiring  might  of  that  mysterious  agent  which 
impels  the  raging  winds  and  upheaves  the  roaring 
billows  ?  Whence  can  come  all  the  power  ?  and 
what  keeps  in  motion  that  wonderful  aqueous  cir- 
culation, which  we  studied  in  the  last  Lecture  ? 

Although  the  origin  of  this  never-ceasing  motion 
may  be  still  concealed,  we  have  at  least  traced  back 
the  power  to  a  proximate  source  in  the  great  central 
luminary  of  our  system.  It  is  the  gentle  influences 


172  RELIGION   AND    CHEMISTRY.  [LECT.  VI. 

of  the  sunbeam  which  raise  the  water  in  vapor,  and 
it  is  the  same  solar  rays  which  keep  in  motion  the 
great  aerial  currents,  spreading  the  clouds  over  the 
earth,  and  distilling  down  their  liquid  treasures  "  to 
satisfy  the  desolate  and  waste  ground,  and  to  cause 
the  bud  of  the  tender  herb  to  spring  forth."  In- 
credible as  it  may  appear,  it  is  actually  the  sun 
which  weaves  the  cloth,  which  feeds  the  fountains 
of  Niagara,  and  it  is  his  delicate  rays  which  rule  in 
the  tempest  and  direct  the  storm.  But  there  are 
other  influences  of  the  sunbeam  still  more  subtile 
than  these,  and  there  are  other  cycles  of  changes,  as 
grand  as  the  aqueous  circulation,  of  which  the  sun 
is  also  the  ever-active  cause, 

Keferring  to  the  table  before  given,  representing 
the  composition  of  the  atmosphere,  you  will  no- 
circuiation  tice  that  the  great  aerial  ocean  contains 
of  carbon.  mOre  than  five  million  billions  of  tons  of 
an  aeriform  substance  called  carbonic  acid.  This 
amount,  although  absolutely  very  great,  is  never- 
theless only  a  small  fraction  of  the  whole  atmos- 
phere, making  up  less  than  a  thousandth  of  its 
total  mass.  A  cubic  foot  of  air  does  not  contain 
more  than  a  quarter  of  a  grain  of  carbonic  acid ; 
yet  there  is  not  one  of  the  atmospheric  constitu- 
ents which  is  more  intimately  associated  with  or- 
ganic life,  or  which  discharges  more  important 
functions.  Although  itself  a  colorless  gas,  carbonic 
acid  consists  of  ordinary  black  charcoal  combined 
with  oxygen,  and  these  elements  are  united  by  one 
of  the  strongest  affinities  known  in  nature.  Yet, 


LECT.VI.]  TESTIMONY   OF   CARBONIC  ACID.  173 

intense  as  this  force  is,  the  power  of  the  sun  is 
greater,  and  his  rays,  acting  on  the  green  leaves  of 
the  plants,  are  constantly  decomposing  the  gas  and 
liberating  the  charcoal,  to  be  incorporated  into  the 
various  forms  of  vegetable  life.  Here,  however,  it 
remains  only  for  a  brief  period ;  for  when  the  plants 
have  finished  their  allotted  term  of  life,  the  charcoal 
again  unites  with  oxygen,  and  in  the  form  of  car- 
bonic acid  is  restored  to  the  atmosphere  by  the 
process  of  combustion  or  decay.  But  frequently, 
before  these  destructive  changes  complete  the  cycle, 
the  charcoal  undergoes  a  further  transformation,  and 
through  the  process  of  digestion  becomes  a  part  of 
the  body  of  the  animal.  Yet  this  transmutation,  as 
a  general  rule,  only  hastens  the  final  result ;  since 
the  processes  of  animal  life  are  very  rapid,  and 
sooner  or  later  the  charcoal  is  burnt  up  in  the 
body  and  breathed  out  into  the  atmosphere,  ready 
to  renew  the  same  series  of  changes.  I  wish  to  ask 
your  attention  this  evening  to  the  evidences  of  de- 
sign which  may  be  discovered  by  studying  this 
wonderful  circulation  of  carbon ;  and  we  shall  find 
that  the  properties  both  of  carbon  and  of  carbonic 
acid  have  been  most  carefully  adjusted  to  the  part 
which  they  play  in  the  great  scheme  of  nature. 
We  might  begin  our  study  at  any  link  of  this  end- 
less chain  of  phenomena ;  but  in  order  to  bring  the 
subject  into  an  orderly  succession  to  our  previous 
trains  of  thought,  let  us  return  to  the  phenomena 
of  combustion,  which  we  considered  in  the  third 
Lecture,  and  study  the  details  of  this  familiar  pro- 
cess a  little  more  closely. 


174  RELIGION  AND    CHEMISTRY.  [LECT.  VI. 

All  fuel,  without  exception,  contains  charcoal,  or, 
as  the  chemists  call  it,  carbon.  Wood,  soft  coal, 
composition  oil,  wax,  and  similar  combustibles,  which 
of  fuel.  burn  with  flame,  contain  besides  carbon 

a  variable  quantity  of  hydrogen  and  oxygen ;  but 
hard  coal,  coke,  and  common  wood  charcoal  are 
almost  pure  carbon.  The  adaptations  of  each  of 
these  classes  of  combustibles  demand  special  notice, 
and  let  us  begin  by  studying  the  evidences  of  de- 
sign which  are  to  be  found  in  an  ordinary  hard- 
coal  fire ;  and  while,  in  imagination,  we  are  pre- 
paring the  fire  to  be  lighted  on  the  grate,  we  may 
study  with  profit  some  of  the  external  properties 
of  the  coal,  for  even  they  betray  the  master  hand 
of  the  Great  Architect. 

Examining  closely  this  lump  of  charcoal,  you  will 
notice  that  it  retains  all  the  delicate  structure  of 
infusibmty  of  the  wood  from  which  it  was  prepared. 
carbon.  Here  is  the  fibrous  bark  next  the  sap- 
wood,  and  then  the  annual  rings,  all  as  on  a  stick 
of  beech-wood ;  and  if  you  will  take  the  pains  to 
make  a  thin  section  of  the  charcoal,  you  will  find, 
on  examining  it  with  a  microscope,  that  the  mi- 
nutest cells  have  been  preserved.  You  know  how 
charcoal  is  made.  The  wood  is  exposed  to  a  high 
temperature  in  the  charcoal  mounds  or  furnace,  by 
which  the  gases  which  it  contains  are  driven  ofi^ 
while  the  charcoal,  not  being  volatile,  remains  be- 
hind. Here,  then,  is  a  remarkable  fact,  —  that,  al- 
though the  wood  has  been  exposed  to  a  red  heat 
in  the  process  of  carbonization,  yet  the  minutest 


LECT.VI.]  TESTIMONY   OF   CARBONIC   ACID.  175 

cells  have  not  been  destroyed  ;  and  it  illustrates  an 
equally  remarkable  quality  of  charcoal,  on  which, 
as  we  shall  see,  its  usefulness  as  fuel  very  greatly 
depends.  Carbon,  in  all  its  forms,  is  absolutely  in- 
fusible. It  does  not  even  soften  at  the  highest 
temperatures  which  can  be  attained  by  art,  and  it  is 
for  this  reason  that  the  charcoal  retains  so  perfectly 
the  structure  of  the  wood.  Were  carbon  fusible  at 
a  red  heat,  the  charcoal  would  run  together  to  a 
shapeless  mass  in  the  mounds  or  furnaces  in  which 
it  is  prepared,  and  did  it  even  soften  at  this  tem- 
perature, the  forms  of  these  delicate  cells  could 
never  have  been  preserved.  Viewed  in  connection 
with  the  volatile  qualities  of  the  other  elements  of 
organized  beings,  the  extreme  fixity  of  carbon  in 
its  uncombined  condition  is  worthy  of  your  special 
attention.  The  only  other  essential  elements  of 
organic  matter  are  oxygen,  hydrogen,  and  nitro- 
gen ;  and  these  three  substances  are  not  only  gases, 
but  gases  which  even  by  the  greatest  cold  or  by 
thousands  of  atmospheres  of  pressure  cannot  be 
condensed  to  the  liquid  condition ;  yet  so  strong  is 
the  tendency  of  carbon  to  remain  solid,  that  it  con- 
denses these  gases  around  itself  in  every  organized 
substance  that  exists.  Carbon  is  thus  the  solid 
substratum  of  organized  matter,  the  skeleton,  as  it 
were,  of  every  organic  form.  How  evidently,  then, 
has  the  attribute  of  infusibility  been  adapted  to 
this  important  function  which  carbon  has  been  ap- 
pointed to  subserve ! 

Examining   again  this  lump  of  charcoal  which 

12 


176  RELIGION   AND    CHEMISTRY.  [LECT.  VI. 

we  are  using  to  kindle  the  fire,  mark  that  it  has 
Bia«k  color  a  black  color  and  is  perfectly  opaque, 
and  opacity.  These  qualities  are  so  evident  to  the 
most  superficial  observation  that  they  are  apt  to 
be  passed  unnoticed,  and  yet  it  is  these  qualities  of 
charcoal  which  make  it  so  valuable  as  the  basis  of 
printing  ink.  All  my  audience  may  not  know  that 
printing  ink  is  a  mixture  of  lamp-black  and  oil,  and 
that  the  letters  on  a  printed  page  are  formed  by 
thin  layers  of  black  charcoal  spread  over  the  white 
paper ;  and  charcoal  is  peculiarly  well  adapted  for 
this  use,  since,  however  finely  subdivided,  it  never 
loses  its  dead  black  color  and  perfect  opacity. 
But  this  property  of  charcoal  would  be  useless 
to  the  scholar  for  diffusing  knowledge,  were  it 
not  combined  with  qualities  still  more  remarkable, 
and  almost  unique.  Carbon  is  not  acted  upon  by 
atmospheric  agents,  and,  moreover,  is  absolutely 
insoluble  in  any  liquid,  with  perhaps  the  exception 
of  melted  iron.  The  letters  of  the  first  Bible  ever 
printed  are  as  black  as  they  were  the  day  they  left 
the  types.  They  have  been  exposed  to  the  action 
of  atmospheric  air  for  four  hundred  years,  and,  were 
carbon  in  the  slightest  degree  acted  upon  by  the 
atmosphere,  they  would  long  since  have  disap- 
peared. As  it  is,  they  will  endure  as  long  as  the 
paper  on  which  they  are  printed  lasts. 

The  almost  unparalleled  insolubility  of  charcoal  is 
a  quality  equally  important  in  this  relation,  for  were 
charcoal  even  to  a  slight  extent  soluble  in  water, 
the  books  of  our  fathers  would  have  been  rendered 


LKCT.VI.]  TESTIMONY   OF   CARBONIC   ACID.  177 

illegible  by  the  dampness  to  which  all  libraries  are 
more  or  less  exposed ;  and  were  carbon  soluble  even 
in  such  liquids  as  alcohol,  ether,  or  the  volatile  oils, 
the  printed  page  would  not  have  been,  as  now,  safe 
from  alteration,  and  all  kinds  of  fraud  would  have 
been  easy.  We  justly  honor  the  names  of  Guten- 
berg and  Faust,  whose  art  has  done  so  much  to  en- 
lighten and  civilize  the  globe,  and  we  bestow  due 
admiration  on  those  improvements  in  the  art  of 
printing,  nowhere  more  developed  than  in  our  own 
land,  which  have  made  the  press  the  great  agent 
of  power,  and  elevated  the  moral  and  intellectual 
above  the  physical  man.  But  while  we  pay  just 
tribute  to  the  genius  of  these  benefactors  of  man- 
kind, let  us  not  forget  that  greater  Benefactor,  who 
was  before  them  all ;  for  in  the  most  familiar  quali- 
ties of  this  piece  of  charcoal,  on  which  the  art  of 
printing  so  greatly  depends,  there  has  been  dis- 
played since  the  foundation  of  the  globe  an  evi- 
dence of  wisdom  and  skill  before  which  all  human 
ingenuity  sinks  into  insignificance. 

But,  my  friends,  the  most  remarkable  attribute  of 
carbon  does  not  appear  in  this  piece  of  charcoal; 
for  of  all   the  chemical  elements  carbon  Modifications 
is  by  far  the  most  protean  in  its  aspects,  of  carbon- 
and  charcoal  is  but  one  of  its  many  manifestations. 
In  the  first  place,  there  are  the  numerous  varieties 
of  coal,  including  charcoal,  coke,  lamp-black,  and 
bone-black,  all  having  the  same  general  properties, 
and   most  of  them  partaking  more  or  less  of  the 
structure  of  the  organic  tissues  from  which  they 


Diamond. 


178  RELIGION   AND    CHEMISTRY.  [LECT.  VI. 

were  made.  But  besides  these  varieties,  which,  al- 
though differing  so  much  in  their  outward  aspect, 
have  all  essentially  the  same  properties,  there  are 
two  entirely  different  states  of  carbon,  differing  as 
much  from  each  other  and  from  common  charcoal 
as  any  two  solids  possibly  could. 

Are  you  aware  that  the  brilliant  gem  you  prize 
so  highly  is  the  same  chemical  element  as  these 
black  coals  ?  The  diamond  is  merely  crys- 
tallized charcoal,  and  although  we  cannot 
crystallize  charcoal  artificially  in  our  laboratories, 
and  do  not  even  know  how  the  diamonds  are 
made  in  the  great  laboratory  of  nature,  yet  there 
is  no  fact  of  chemistry  better  established  than  this. 
To  those  who  are  not  familiar  with  the  results 
of  modern  chemistry,  it  seems  almost  incredible, 
and  even  the  chemist  can  hardly  believe  the  truth 
while  he  affirms  it.  It  is  at  utter  variance  with 
the  whole  doctrine  of  his  science ;  it  cannot  be 
reconciled  with  any  of  his  previous  conceptions, 
and  constantly  reminds  him  of  the  limitations  of 
his  knowledge  and  the  uncertainty  of  his  philos- 
ophy. And,  turning  to  the  more  familiar  aspects 
of  the  subject,  how  singular  the  fact,  and  how 
typical  of  the  universality  of  Christian  brother- 
hood, that  He  who  "hath  made  of  one  blood  all 
nations  of  men,"  should  have  also  made  of  the 
same  material  the  priceless  brilliant  which  adorns 
the  diadem  of  the  prince,  and  the  soot  which  be- 
grimes the  cabin  of  the  humblest  peasant !  How 
different  the  estimation  in  which  these  two  forms 


LECT.VL]  TESTIMONY   OF   CARBONIC   ACID.  179 

of  carbon  are  held  !  and  yet,  if  the  marks  of  Divine 
wisdom  can  give  nobility  to  a  substance,  the  one  is 
as  excellent  as  the  other. 

But  carbon  exists  in  still  a  third  modification,  dif- 
fering as  much  from  the  diamond  as  that  differs 
from  charcoal.  Every  one  who  has  used 
a  common  lead  pencil  is  familiar  with 
graphite,  and  it  is  a  fact  as  remarkable  as  the 
one  just  noticed,  that  the  same  carbon  which 
forms  the  letters  of  a  printed  page  fills  also  the 
lines  of  the  pencil  sketch.  Graphite  is  simply  a 
modification  of  charcoal,  and  if  this  fact  is  not  so 
well  known  as  the  humble  relationship  of  the  dia- 
mond, it  probably  arises  from  the  circumstance 
that  graphite  has  been  generally  called  plumbago, 
or  black-lead,  a  misnomer  which  has  given  a  very 
erroneous  conception  of  its  nature.  Graphite  is 
frequently  mixed  with  impurities,  but  it  never  con- 
tains lead,  and  in  its  finest  condition  it  is  nearly 
pure  carbon.  Compare  now  graphite  with  the  dia- 
mond. Could  there  be  two  substances  more  un- 
like ?  the  one  the  softest  of  minerals,  the  other  the 
very  hardest ;  the  one  dull  and  opaque,  the  other 
brilliant  and  transparent.  But  besides  these  exter- 
nal differences  they  have  also  a  different  crystalline 
form,  a  different  specific  gravity,  a  different  capaci- 
ty for  heat,  and,  in  fine,  excepting  that  they  are 
both  infusible  and  combustible,  there  is  not  one 
point  of  resemblance  between  them.  How  then, 
you  will  ask,  do  we  know  that  they  are  both  the 
same  substance  as  charcoal  ?  Simply  because,  when 


180  RELIGION   AND    CHEMISTRY.  [LECT.  VI. 

combined  with  oxygen,  they  all  yield  the  self-same 
compound. 

All  three  of  the  modifications  of  carbon  are 
combustible,  although  they  take  fire  at  very  dif- 
ferent temperatures.  Charcoal  will  burn  at  a  red 
heat,  the  diamond  at  a  white  heat,  while  graph- 
ite requires  the  highest  temperature  which  can 
be  attained  by  art.  But  however  different  may 
be  the  temperatures  required,  the  process  is  the 
same  in  all  cases  and  the  result  is  the  same.  The 
burning  is  simply  combination  with  the  oxygen  of 
the  air,  and  the  result  of  that  combination  is  car- 
bonic-acid gas.  Moreover,  it  has  been  proved  by 
the  most  careful  experiments  that  a  given  weight 
of  either  substance  yields  precisely  the  same  weight 
of  carbonic-  acid.  Chemically  considered,  then,  the 
diamond,  graphite,  and  charcoal  are  the  same  sub- 
stance, although,  physically  regarded,  no  substances 
could  be  more  unlike.  Chemical  identity,  there- 
fore, does  not  consist  in  identity  of  properties,  and 
we  must  admit  that  the  same  chemical  element 
may  manifest  itself  under  utterly  different  physical 
aspects. 

This  remarkable  phenomenon,  which  has  been 
fully  recognized  only  of  late  years,  has  been  called 
by  chemists  allotropism,*  and  the  diamond, 
plumbago,  and  charcoal  are  different  allo- 
tropic  modifications  of  the  element  carbon.     Such 
differences  of  manifestation,  moreover,  are  not  con- 
fined to  carbon,  nor  are  they  exceptional  occur- 

*  Derived  from  two  Greek  words  signifying  difference  of  condition. 


LECT.  VI.]  TESTIMONY   OP   CARBONIC   ACID.  181 

rences  among  the  elements.  We  have  already 
seen  that  oxygen  may  exist  in  an  active  and  in  a 
passive  modification,  which  stand  in  as  striking  an 
antithesis  to  each  other  as  the  diamond  and  char- 
coal, and  the  same  is  true  of  the  different  conditions 
of  sulphur,  phosphorus,  and  silicon.  Again,  these 
phenomena  are  not  limited  to  the  elementary  sub- 
stances, for  they  have  been  observed  in  many  com- 
pounds as  well,  and  every  year  enriches  our  knowl- 
edge with  fresh  examples.  In  what,  then,  are  such 
developments  to  end  ?  If  substances  so  utterly  un- 
like as  the  diamond,  graphite,  and  charcoal  are 
merely  modifications  of  the  same  element,  why  may 
not  all  substances  be  merely  different  allotropic 
states  of  a  few  universal  principles,  or  possibly  of 
only  one  single  essence  ?  Such,  and  many  similar 
questions,  arise  in  the  mind  of  the  chemist  while 
contemplating  these  obscure  phenomena.  They 
cannot  be  answered  in  the  present  state  of  chemis- 
try, and  they  throw  a  degree  of  uncertainty  and 
doubt  on  its  whole  philosophy.  I  shall  have  oc- 
casion to  dwell  upon  this  subject  more  at  length 
in  another  Lecture,  and  have  adduced  the  facts  at 
this  time  chiefly  as  further  illustrations  of  that  fer- 
tility of  resources  which  so  strikingly  marks  all  the 
results  of  creative  skill.  To  me  this  characteristic  of 
the  works  of  nature  is  one  of  the  most  convincing 
evidences  of  divinity.  While  studying  the  simple 
adaptation  of  means  to  ends  which  we  find  every- 
where around  us,  we  recognize  in  the  plan  some- 
thing analogous  to  the  creations  of  human  skill,  and 


182  EELIGION   AND    CHEMISTRY.  [LECT.  VI. 

we  almost  feel  a  conscious  relationship  with  its  Au- 
thor. But  when  we  consider  this  incomprehensi- 
ble power,  by  which  the  same  substance  has  been 
endowed  with  entirely  different  and  incompatible 
properties,  and  not  only  this,  but  has  been  adapted 
in  each  condition  with  equal  skill  to  produce  the 
most  opposite  and  seemingly  irreconcilable  results, 
we  are  also  made  to  feel  most  keenly,  that,  al- 
though man  was  created  in  the  image  of  his  Maker, 
he  resembles  the  Divine  Original  only  as  the  finite 
can  resemble  the  Infinite.  "  For  my  thoughts  are 
"  not  your  thoughts,  neither  are  your  ways  my 
"  ways,  saith  the  Lord.  For  as  the  heavens  are 
"  higher  than  the  earth,  so  are  my  ways  higher 
"than  your  ways,  and  my  thoughts  than  your 
« thoughts." 

Of  all  the  properties  of  coal,  the  one  with  which 
we  are  most  familiar  is  its  combustibility;  and 
Burning  of  while  we  have  been  discussing  its  exter- 
hardcoai.  na|  properties,  the  hard-coal  fire  has  been 
built  in  the  grate,  and  it  is  ready  to  be  lighted. 
The  combustion  of  coal  in  one  or  the  other  of  its 
varieties  is  the  great  source  of  all  the  artificial  heat 
used  by  man.  Although  so  entirely  passive  towards 
atmospheric  agents  at  the  ordinary  temperature, 
yet  when  heated  to  a  red  heat  it  takes  fire  and 
combines  with  the  oxygen  of  the  air  with  great 
rapidity.  The  burning  of  coal  is  so  familiar  to 
every  one  that  it  would  seem  hardly  necessary  to 
dwell  upon  the  subject  here.  But  although  the 
experiment  is  repeated  every  day  in  every  grate 


LECT.VI.]  TESTIMONY    OF   CARBONIC   ACID.  183 

of  this  city,  and  although  it  has  been  familiar  to 
you  all  from  infancy,  there  are,  nevertheless,  phe- 
nomena connected  with  it  which  few  have  observed 
and  still  fewer  fully  appreciated.  It  is  a  great  mis- 
take, but  a  mistake  too  frequently  made  even  by 
scientific  men,  to  suppose  that  new  knowledge  can 
be  gathered  only  from  the  unexplored  fields  of  sci- 
ence, when  by  the  most  familiar  walks  of  life  there 
are  countless  riches  of  truth  which  the  reapers  in 
the  hurry  of  the  harvest  have  passed  unnoticed,  and 
which  will  abundantly  reward  the  careful  gleaners. 
In  the  coal  fire  on  which  you  daily  gaze,  there  is 
enough  to  be  discovered  to  engross  the  attention 
of  the  most  diligent  student  of  nature.  Let  us  see, 
therefore,  if  we  too  cannot  learn  something  new  at 
least  to  us  from  the  burning  coals. 

The  first  fact  to  which  I  would  call  your  atten- 
tion, is  the  difficulty  experienced  in  lighting  coal. 
In  order  to  kindle  the  fire  we  have  placed  p0int0figni- 
on  the  bottom  of  the  grate,  first,  some  tiOQ- 
shavings,  then  some  charcoal,  and  last  of  all  the 
hard  anthracite  coal.  We  can  readily  set  fire  to 
the  shavings  with  a  match,  and  they  in  their  turn 
will  ignite  the  charcoal ;  but  it  requires  the  intense 
heat  of  the  burning  charcoal  to  ignite  the  anthracite. 
Charcoal  will  not  burn  unless  at  a  full  red-heat, 
and  hard  coal  requires  a  still  higher  temperature. 
But  notice  now  another  fact :  when  once  inflamed, 
the  heat  evolved  by  the  combination  of  the  carbon 
with  oxygen  is  sufficient  to  sustain  the  tempera- 
ture at  the  point  of  ignition.  Here,  again,  we  see 


184  RELIGION   AND    CHEMISTRY.  [LECT.  VI. 

most  admirably  illustrated  the  adaptation  of  the 
properties  of  the  chemical  elements  to  entirely  dif- 
ferent ends.  In  order  that  carbon  might  serve  as 
the  solid  substratum  of  all  organized  beings,  it  was 
necessary  that  it  should  be  made  unalterable  by 
the  air  within  the  limits  of  terrestrial  temperature, 
but  at  the  same  time  the  economy  of  nature  re- 
quired that  it  should  be  made  combustible,  that 
is,  endowed  with  strong  affinities  for  oxygen ;  yet 
these  affinities  have  been  so  carefully  regulated, 
that  they  are  called  into  play  only  at  a  high  tem- 
perature, and  are  thus  placed  entirely  under  the 
control  of  man. 

Now  that  the  coal  is  in  violent  combustion,  com- 
bining rapidly  with  oxygen,  notice  that  it  burns 
Bright  light  entirely  without  flame.  "We  have  here 
but  no  flame.  rapj<j  chemical  combination,  with  all  the 
phenomena  of  active  burning,  and  yet  no  flame, 
simply  because  flame  is  always  burning  gas,  and  in 
a  hard-coal  fire  it  is  not  a  gas,  but  a  highly  fixed 
solid,  that  is  burning.  Charcoal  and  anthracite  are 
almost  the  only  combustibles  which  burn  in  this 
way.  Most  others,  even  when  naturally  solids,  are 
converted  into  gases  at  a  high  temperature,  and 
therefore  burn  with  flame  \  but  carbon  in  all  its 
forms,  when  uncombined,  persistently  retains  its 
solid  condition,  even  in  the  hottest  fire. 

Remark,  also,  that  this  combustion  is  attended 
with  a  very  bright  white  light,  and  compare  it 
with  the  more  violent  combustion  of  hydrogen, 
with  which  most  of  my  audience  must  be  familiar. 


LECT.VL]  TESTIMONY   OF   CARBONIC   ACID.  185 

Hydrogen  burns  with  a  flame,  because  it  is  a  gas ; 
but  this  flame  is  almost  invisible,  because  gases, 
however  intensely  heated,  do  not  emit  a  bright  light. 
The  charcoal  burns  without  flame  because  it  is  a 
permanent  solid,  but  for  this  very  reason  it  emits  a 
great  amount  of  pure  white  light.  So  far,  at  least, 
as  ordinary  experience  extends,  white  light  is  emit- 
ted only  from  ignited  solid  matter.*  Therefore 
neither  white  light  nor  flame  is  a  necessary  con- 
comitant even  of  the  most  rapid  combustion,  the 
first  depending  solely  on  the  solid,  and  the  last  on 
the  aeriform,  condition  of  the  burning  substance. 
If,  as  in  the  burning  of  a  candle,  both  flame  and 
white  light  attend  the  process,  it  is  because  both 
solid  and  aeriform  matter  are  there  burning ;  and 
when  we  come  to  examine  this  phenomenon  more 
closely,  we  shall  find  that  the  result  is  produced  by 
a  most  beautiful  adaptation  of  properties. 

Let  me  next  call  your  attention  to  the  impor- 
tance of  the  infusibility  of  charcoal  in  connection 
with  its  use  as  fuel.  However  high  the 

.  c  Use  as  fuel 

temperature  at  which  it  burns,  however  depends  on  its 
intense  the  furnace  heat,  charcoal  never 

*  I  use  the  phrase  white  light  because  an  ignited  gas  or  vapor  may 
emit  a  colored  light,  and  it  has  been  found  that  the  color  is  in  each  case 
determined  by  the  chemical  composition  of  the  ignited  mass ;  but  the 
light  emitted  from  the  gases  or  vapors  of  which  the  flames  of  ordinary 
combustibles  consist,  is  at  best  very  feeble.  The  light  of  such  flames,  as 
will  soon  appear,  comes  almost  entirely  from  solid  particles  of  charcoal, 
and  when  these  from  any  cause  are  not  present,  the  flame  only  yields  a 
very  faint  blue  light.  The  appearance  of  the  whole  flame  is  then  the 
same  as  that  which  may  always  be  seen  near  the  orifice  of  a  bat-wing 
gas-burner. 


186  RELIGION   AND    CHEMISTRY.  [LECT.  VI. 

loses  its  solid  condition,  and  on  this  wholly  depends 
its  application  for  generating  heat.  Were  coal  fusi- 
ble, even  at  a  very  high  temperature,  it  would  melt 
and  run  out  from  our  grates  and  furnaces,  and  the 
genial  fire  could  not  as  now  have  been  localized  on 
the  hearth.  The  enjoyment  of  the  social  fireside 
is  thus  closely  connected  with  a  familiar  property 
of  this  wonderful  element. . 

But  our  fire  is  slowly  burning  away,  and  already 

more  than  one  half  of  the  coal  has  been  consumed. 

What  has  become  of  it  ?     Do  you  point 

The  products 

of  combustion  to  the  ashes  ?  These  are  only  the  earthy 
impurities,  which  are  more  or  less  mixed 
with  the  pure  carbon,  and  constitute  but  a  small 
fraction  of  the  whole  mass  of  the  coal.  The  carbon 
itself  has  combined  with  the  oxygen  of  the  air  and 
formed  a  colorless  and  invisible  gas,  which  has  es- 
caped by  the  chimney.  I  have  already  stated  in 
my  Lecture  on  Oxygen,  that  this  gas  has  acid  quali- 
ties, and  we  have  named  it  carbonic  acid.  Reflect 
now  on  the  importance  of  the  circumstance,  that 
this  compound  of  oxygen  and  carbon  is  aeriform, 
and  consider  what  a  marked  evidence  of  design 
and  adaptation  is  to  be  found  in  the  very  fact  that 
the  products  of  ordinary  combustion  are  invisible 
gases,  which  ascend  our  chimneys  and  are  wafted 
away  by  the  currents  of  the  atmosphere.  As  the 
common  experience  is  confined  to  the  burning  of 
coal,  wood,  oil,  and  similar  combustibles,  consisting 
mainly  of  carbon  and  hydrogen,  men  naturally  as- 
sociate with  smoke  the  idea  of  a  gas,  and  are  apt 


LECT.  VI.]  TESTIMONY   OF   CARBONIC   ACID.  187 

to  think  that  the  aeriform  condition  is  a  necessary 
result  of  the  nature  of  things.  But  it  is  not  so. 
This  peculiar  provision  in  the  case  of  carbon  and 
hydrogen  is  an  exception  to  the  general  rule.  The 
two  combustible  elements  which  are  most  closely 
allied  to  carbon  in  all  their  properties,  boron  and 
silicon,  not  only  form  solids  by  burning,  but  two  of 
the  most  fixed  solids  known  in  nature,  one  of 
which,  silica,  constitutes,  as  we  have  seen,  at  least 
one  half  of  the  rocky  crust  of  our  globe ;  and  the 
same  is  true  of  almost  all  the  other  combustible 
elements.  A  very  interesting  experiment  in  illus- 
tration of  this  fact  may  be  made  by  burning  a  piece 
of  phosphorus  under  a  dry  glass  receiver.  The 
smoke  of  phosphorus  is  solid,  and  it  will  fall  in 
thick  white  flakes,  producing  within  the  glass  the 
appearance  of  a  miniature  snow-storm.  Picture  to 
yourself  the  desolation  which  would  be  produced 
were  the  order  of  nature  so  far  changed  as  to  make 
the  products  of  burning  coal  like  those  of  burning 
phosphorus.  Every  furnace  would  become  a  vol- 
cano, and  we  should  soon  be  buried  beneath  the 
smoke  of  our  own  fires.  "When,  now,  we  consider 
that  a  special  provision  has  been  made  in  the  case 
of  that  substance  whose  combustion  administers  to 
our  wants  by  evolving  light  and  heat,  what  evi- 
dence does  it  open  to  us  of  the  all- wise  forethought 
of  the  Great  Original ! 

But  this  is  not  all.  Let  me  now  call  your  atten- 
tion to  an  additional  fact  in  regard  to  the  carbonic 
acid  which  is  escaping  from  our  coal  fire.  The  gas  is 


188  RELIGION   AND    CHEMISTRY.  [LECT.  VI. 

entirely  devoid  both  of  odor  and  of  taste,  and,  more- 
over, when  in  a  sufficiently  diluted  condi- 

The  products  •      -i         •  i 

of  combustion  tion  it  can  be  breathed  with  impunity. 
Consider  what  an  amount  of  this  product 
is  daily  formed,  and  you  will  then  be  able  to  appre- 
ciate the  importance  of  this  circumstance.  The 
amount  of  carbonic  acid  which  escapes  from  an  av- 
erage-sized iron  blast-furnace  in  the  course  of  a 
single  hour  is  equal  to  at  least  two  tons,  and  the 
amount  which  is  generated  even  by  our  coal  fire  is 
surprisingly  large.  Moreover,  no  less  than  two 
thousand  tons  *  of  this  gas  are  breathed  into  the  air 
by  the  population  of  this  city  in  a  single  day.  If 
carbonic  acid  had  been  a  pungent  or  corrosive  gas, 
coal  could  not  have  been  used  as  fuel ;  for  its  com- 
bustion, like  that  of  sulphur,  would  soon  have  ren- 
dered the  air  irrespirable.  But  so  entirely  destitute 
is  it  of  any  perceptible  odor  or  taste,  that,  although 
it  has  been  evolved  in  these  immense  quantities 
from  every  fire  lighted  by  man  since  he  appeared 
on  the  globe,  it  so  entirely  escaped  notice  that  its 
existence  was  not  even  suspected  until  it  was  dis- 
covered by  Dr.  Black  about  a  century  ago. 

There  is  still  another  remarkable  phenomenon 
attending  a  coal  fire,  which,  although  it  cannot  be 
The  smoke  has  ma^e  evident  to  the  senses,  has  been  sub- 
the  same  voi-  gtantiated  again  and  again  by  the  most 

ume  as  the  . 

oxygen  con-      accurate   experiments.      The   volume   of 
carbonic-acid  gas  formed  by  the  combus- 
tion is  exactly  equal  to  the  volume  of  oxygen  con- 

*  Calculated  for  400,000  inhabitants. 


LECT.VI.]  TESTIMONY   OF   CARBONIC   ACID.  189 

sumed.  It  is  a  consequence  of  this  fact,  that  the 
volume  of  the  air  is  not  in  the  slightest  degree  in- 
creased by  the  vast  quantity  of  carbonic-acid  gas 
which  is  daily  poured  into  it.  The  gas  occupies 
precisely  the  same  space  as  the  oxygen  removed 
during  the  combustion,  and  thus  the  equilibrium  of 
the  atmosphere  is  not  disturbed.  It  is  true  that  we 
probably  cannot  see  all  the  bearings  of  this  simple 
provision ;  but  we  know  enough  to  recognize  in  it 
a  most  marked  evidence  of  design. 

The  last  fact  in  connection  with  the  coal  fire  to 
which  I  would  direct  your  attention  is  the  large 
amount  of  heat  which  the  combustion  of  Heat  Of 
coal  liberates,  and  on  which  its  use  as  fuel  combastion- 
very  largely  depends.  One  pound  of  charcoal,  in 
burning  completely,  generates  sufficient  heat  to 
raise  the  temperature  of  80.8  pounds  of  water  from 
the  freezing  to  the  boiling  point.  Every  pound  of 
charcoal  may,  therefore,  be  regarded  as  containing 
sufficient  heat  to  boil  eighty  pounds  of  ice-cold 
water.  What  a  vast  amount  of  heat  then  lies 
buried  in  those  inexhaustible  beds  of  mineral  coal, 
in  which  our  country  is  so  rich !  And  have  we  not 
another  remarkable  evidence  of  Divine  wisdom  in 
the  fact  that  carbon,  a  substance  which,  on  account 
of  its  infusibility  and  other  qualities,  is  so  well 
adapted  for  fuel,  has  been  made  a  great  reser- 
voir of  heat,  from  which  man  can  draw  an  unlim- 
ited supply  ?  When  we  remember  that  this  heat, 
through  the  expansion  of  steam,  may  be  converted 
into  mechanical  force,  and  that  hence  these  beds  of 


190  RELIGION   AND    CHEMISTRY.  [LECT.  VI. 

coal  are  not  only  magazines  of  heat,  but  stores 
of  force,  which  have  been  accumulating  from  the 
foundation  of  the  globe  for  the  use  of  civilized  man, 
and  when  we  reflect  that  it  is  this  force  which  is  ani- 
mating our  commerce,  weaving  our  cloth,  forging 
our  iron,  and  impelling  the  printing-press,  how  can 
we  express  our  praises  of  the  foresight  of  that  Prov- 
idence which  endowed  coal  with  such  wonderful 
qualities,  made  it  a  vast  repository  of  heat  and 
of  force,  and  then  spread  it  bountifully  over  the 
globe  ? 

We  have  discovered,  my  friends,  all  these  won- 
derful indications  of  design  and  adaptation  in  this 
simple  experiment,  so  familiar  as  to  be  almost  trite, 
so  frequently  repeated  as  to  pass  unnoticed,  and 
they  are  constantly  speaking  to  us  of  the  great 
Author  of  nature  from  the  fireside  of  every  home, 
and  from  the  furnace  of  every  work-shop  in  the 
land.  The  followers  of  Zoroaster  still  worship,  in 
India,  fire  as  divinity,  and  regard  these  burning 
coals  as  sacred.  Behind  this  superstition  and  idol- 
atry there  is  concealed  true  wisdom,  by  which  we 
may  well  profit.  Fire  is  neither  divinity,  nor  yet 
its  emblem.  It  has  no  other  reality  than  as  a  phe- 
nomenon attending  a  chemical  change ;  but  in  the 
qualities  with  which  charcoal  has  been  endowed  in 
order  to  produce  this  phenomenon,  in  the  delicate 
adjustment  of  forces  by  which  the  destructive 
change  is  confined  within  due  limits,  there  are  in- 
dications of  divinity  which  may  well  make  us 
thoughtful,  and  consecrate  with  additional  sanctity 


LKCT.  VI.]  TESTIMONY   OF   CARBONIC   ACID.  191 

the  family  hearth ;  and  if  I  have  succeeded,  how- 
ever imperfectly,  in  making  audible  to  your  intel- 
lectual ear  this  mute  eloquence  of  burning  coal, 
our  time  has  not  been  spent  in  vain. 

I  have  thus  far  drawn  all  my  illustrations  from 
the  burning  of  charcoal  and  hard  coal,  simply  be- 
cause these  familiar  forms  of  fuel  are  near-  Buming  of 
ly  pure  carbon,  and  the  phenomena  at-  80ftcoal- 
tending  their  combustion  are  comparatively  simple. 
They  burn,  as  we  have  seen,  without  flame,  and  for 
the  reason  that  carbon  does  not  volatilize,  even  at 
the  highest  temperatures.  It  is  different,  however, 
with  soft  coal,  wood,  oil,  wax,  and  all  other  combus- 
tible materials  which  are  used  for  generating  light. 
They  do  not  consist  wholly  of  carbon ;  but  this  ele- 
ment is  always  combined  with  hydrogen,  and  most 
of  these  combustibles  contain  also  in  addition  a  lim- 
ited amount  of  oxygen.  When  heated,  they  all 
evolve  common  illuminating-gas,  and  for  this  reason 
burn  with  a  flame.  In  fact,  the  gas  we  are  burn- 
ing here  to-night  was  made  from  just  such  ma- 
terials. If  you  will  visit  the  gas-works  of  this 
city,  you  will  see  long  rows  of  iron  retorts,  firmly 
built  into  large  brick  furnaces.  In  these  retorts 
the  gas  is  made,  and  they  are  connected  by 
means  of  a  complicated  system  of  tubes  with  all 
the  numberless  gas-burners  of  this  large 

Manufacture 

city.     Every  few  hours   the   retorts   are  of  muminat- 
charged  with   soft  coal,  which  soon  be- 
comes heated  to  a  low  red  heat.    At  this  tempera- 
ture it  slowly  gives  off  gas,  and  it  is  the  gas  thus 

13 


192  RELIGION   AND    CHEMISTRY.  [LECT.  VI. 

formed  which  is  now  illuminating  this  hall.  After 
three  or  four  hours  the  gas  has  been  all  driven  off, 
but  there  is  still  left  in  the  retorts  the  greater 
part  of  the  carbon  of  the  coal,  in  a  condition  which 
is  called  coke.  This  is  then  removed  and  used  for 
feeding  the  furnaces,  and  a  new  charge  of  soft  coal 
is  introduced  in  its  place.  Coke  is  an  excellent 
fuel,  but,  like  charcoal,  it  burns  without  flame. 

The  processes  which,  in  the  manufacture  and 
use  of  illuminating-gas,  are  spread  over  a  whole 
city,  are  united  in  every  soft-coal  fire.  The  gas 
which  is  burning  at  this  jet  was  generated  in 
the  retorts  of  the  gas-works,  and  brought  here  in 
iron  tubes  to  be  burnt.  In  the  grate  the  gas  is 
made  and  burnt  in  successive  moments,  but  the 
process  is  identical  in  both  cases.  When  you  throw 
a  fresh  supply  of  soft  coal  on  the  grate,  the  first 
effect  of  the  heat  is  to  generate  illuminating-gas, 
which  at  once  takes  fire  and  burns  with  a  brilliant 
blaze.  But  after  some  time  the  flame  ceases,  be- 
cause all  the  volatile  elements  of  the  coal  have 
been  expelled,  and  the  coke,  which  is  left,  merely 
smoulders,  like  charcoal  or  anthracite.  What  is 
true  of  soft  coal  is  also  true  of  wood  and  of  all 
this  class  of  combustibles. 

Flame,  as  I  have  before  stated,  is  in  all  cases 
burning  gas.  As  we  are  generally  familiar  with  it, 
Nature  of  flame  is  a  cloud  of  illuminating-gas  com- 
flame.  bining  on  its  exterior  surface  with  the 

oxygen  of  the  air.  In  a  gas  lamp  the  gas  is  sup- 
plied ready  made  at  the  jet.  In  an  oil  lamp  or  a 


LECT.VI.]  TESTIMONY    OP   CARBONIC   ACID.  193 

candle,  the  gas  is  manufactured  as  fast  as  it  burns. 
The  use  which  we  make  of  the  flame  in  all  these 
cases,  is  to  generate  light,  and  the  qualities  of  car- 
bon have  been  most  admirably  adjusted  to  produce 
that  result.  This  is  the  point  which  I  wish  next  to 
illustrate,  and  we  shall  understand  this  beautiful 
example  of  adaptation  more  readily  by  analyzing 
the  burning  of  some  one  of  the  light-generating  ma- 
terials. I  will  therefore  select  a  common  wax  can- 
dle as  my  example,  because  it  is  familiar  to  every 
one,  and  illustrates  all  the  points  I  have  in  view. 

Nothing  could  be  simpler  than  the  candle  itself. 
It  is  a  long  cylinder  of  wax  formed  around  a  string 
made  of  loose  cotton  threads,  which  we  call  the 
wick.  The  wax,  that  familiar  secretion  of  the 
honey-bee,  is  composed  chemically  of  carbon,  hy- 
drogen, and  a  little  oxygen ;  the  wick,  as  the  mi- 
croscope would  show  us,  is  merely  a  collection  of 
fine  vegetable  tubes.  Let  us  now  light  the  candle. 
For  that  purpose  we  apply  the  flame  of  a  friction 
match  to  the  end  of  the  wick,  and  mark  the  result. 
The  heat  of  the  match  melts  the  wax  around  the 
base  of  the  wick,  and  now  the  peculiar  virtue  of 
these  vegetable  tubes  comes  into  play.  All  fine 
tubes  have  the  power  of  sucking  up  liquid,  and  the 
finer  the  tube,  the  greater  the  height  to  which  the 
liquid  is  thus  elevated.  The  tubes  of  the  wick 
are  vastly  finer  than  any  that  man  can  make,  and 
the  melted  wax  is  at  once  drawn  up  to  the  flame 
of  the  match.  There  it  is  volatilized  by  the  high 
temperature,  and  a  cloud  of  red-hot  combustible 


194  RELIGION   AND   CHEMISTRY.  [LECT.  VI. 

gas  forms  around  the  summit  of  the  wick.  Like 
the  rain-drop,  or  any  other  fluid  body  in  a  free 
state,  it  assumes  a  spherical  form,  but  being  much 

lighter  than  the  air,  this 
sphere  of  gas  no  sooner 
forms  than  it  begins  to  as- 
cend, and,  being  very  com- 
bustible, is  burnt  up  by 
the  oxygen  of  the  air  with 
great  rapidity,  so  that  be- 
fore it  has  risen  an  inch 
from  the  wick  it  is  reduced 
to  a  point.  Meanwhile, 
however,  the  first  sphere  is  followed  by  others,  which 
in  rapid  succession  meet  with  the  same  fate,  and  at 
any  moment  we  have  a  large  number  of  these  little 
spheres,  one  above  the  other,  rapidly  diminishing  in 
size  from  the  lowest  to  the  highest,  which  has  then 
become  a  mere  point.  Hence  results  the  familiar 
conical  form  of  the  flame.  But  our  match  is  long 
since  burnt  out,  and  what,  you  will  ask,  now  vola- 
tilizes the  wax  ?  Solely  the  heat  evolved  by  the 
burning  gas.  This  heat  converts  the  wax  into 
vapor  as  fast  as  it  creeps  up  the  wick,  and  thus  the 
flame  being  constantly  supplied  with  combustible 
gas,  the  candle  continues  to  burn  until  it  is  all  con- 
sumed. The  candle-flame  is  then  merely  a  cone 
of  volatilized  wax,  rapidly  combining  on  its  exte- 
rior surface  with  the  oxygen  of  the  air,  and  as  rap- 
idly replenished  from  below  by  the  constant  con- 
version of  fresh  wax  into  vapor.  In  this  process 


LECT.  VI.]  TESTB10NY   OP   CARBONIC   ACID.  195 

light  and  heat  are  evolved ;  but  these  are  gener- 
ated solely  on  the  exterior  surface  of  the  flame, 
where  the  burning  takes  place.  Within  it  is  per- 
fectly dark,  as  can  be  easily  shown  by  pressing 
down  upon  it  a  piece  of  window-glass,  through 
which  the  interior  may  be  seen.  Let  us  now  study 
this  chemical  process  more  carefully,  as  it  is  on  a 
very  delicate  play  of  affinities  that  the  whole  illu- 
minating power  of  the  flame  depends. 

The  combustible  gas  formed  from  wax  is  composed 
essentially  of  charcoal  and  hydrogen.  The  light  and 
combustible  hydrogen  has  so  great  a  tendency  to 
retain  its  aeriform  condition,  that,  when  combined 
with  carbon,  it  renders  even  this,  the  most  fixed  of 
all  the  elements,  aeriform ;  but  the  moment  the 
bonds  of  chemical  affinity  are  loosened,  the  carbon 
resumes  its  solid  condition.  Such  a  change  takes 
place  in  the  flame,  and  it  is  the  particles  of  solid 
charcoal  thus  liberated  which  render  it  luminous. 
Of  the  two  elements  of  the  gas,  hydrogen  has  the 
greatest  affinity  for  oxygen,  and  therefore  burns 
first,  momentarily  setting  free  the  carbon,  which  is 
sprinkled  in  a  fine  powder  through  the  burning  gas. 
This  is  at  once  intensely  heated,  and  each  glowing 
particle  becomes  a  centre  of  radiation,  throwing  out 
its  luminous  pulsations  in  every  direction.  The 
sparks  last,  however,  but  an  instant;  for  the  next 
moment  the  charcoal  is  itself  consumed  by  the 
fierce  oxygen,  now  aroused  to  full  activity,  and 
nothing  but  a  transparent  gas  rises  from  the  flame. 
But  the  same  process  continues ;  other  particles 


196  RELIGION   AND    CHEMISTRY.  [LECT.  VI. 

succeed,  which  become  ignited  in  their  turn,  and 
hence,  although  the  sparks  are  evanescent,  the 
light  is  continuous. 

Thus  it  appears  that  all  our  artificial  light,  the 
light  which  we  are  enjoying  this  evening,  depends 
upon  this  provision,  by  which  the  particles  of  char- 
coal linger  for  a  moment  in  the  flame  before  they 
are  burnt.  Let  me  again  repeat,  white  light  is 
emitted  only  by  ignited  solid  matter.  The  flame 
of  pure  hydrogen  gives  very  little  light,  because 
there  are  in  it  no  solid  particles,  and  were  the 
affinity  of  oxygen  for  carbon  slightly  greater  than 
at  present,  the  flame  of  the  candle  would  be  as 
little  luminous  :  then  the  carbon  would  burn  simul- 
taneously with  the  hydrogen,  and  there  would  be 
no  pulverized  charcoal  in  the  flame  to  radiate  light. 
On  the  other  hand,  were  the  affinity  of  oxygen 
for  carbon  a  little  less  than  at  present,  the  carbon 
particles  would  not  burn  in  the  flame,  but  would 
escape  from  it  in  clouds  of  dense  soot.  Our  Heav- 
enly Father  has  so  carefully  adjusted  the  relative 
affinity  of  oxygen  for  the  two  elements  of  these 
light-giving  gases,  that  the  hydrogen  should  burn 
a  small  fractional  part  of  a  second  before  the  car- 
bon. During  this  brief  interval  of  time,  imper- 
ceptible to  our  unaided  senses,  the  solid  particles 
of  charcoal  are  set  free,  become  ignited,  and  give 
motion  perhaps  to  a  single  wave  of  light ;  but  the 
instant  after,  they  too  rush  into  combination  with 
the  great  fire-element,  and  not  a  particle  is  left  to 
dim  the  transparency  of  the  air.  The  smallest 


LECT.  VI.]  TESTIMONY   OF   CARBONIC   ACID.  197 

variation  in  either  force  would  destroy  the  adjust- 
ment by  which  this  result  is  produced,  and  our 
lamps  and  candles  would  cease  to  give  their  light. 
How  delicate  the  adjustment !  How  beneficent  the 
result !  How  evident  the  design  ! 

To  me  the  marks  of  God's  designing  hand  are 
more  conspicuous  in  that  familiar  candle-flame  than 
in  the  grand  cycles  of  astronomy,  or  in  the  wonder- 
ful mechanism  of  the  human  body.  I  return  to  it 
again  and  again  with  renewed  confidence,  and  al- 
ways find  fresh  satisfaction  and  increasing  faith. 
There  are  many  who  believe  with  Laplace  that  this 
glorious  system  of  suns  and  planets,  with  all  its 
complex  movements  and  adjustments,  might  be 
evolved  out  of  a  nebulous  chaos  by  the  sole  action 
of  the  primary  laws  of  motion;  and  now,  after  the 
great  French  mathematician  has  furnished  a  world 
to  begin  with,  a  modern  naturalist  asks  us  to  be- 
lieve that  this  hand  of  mine,  with  all  its  wonderful 
combination  of  nerves,  bones,  and  muscles,  was  de- 
veloped out  of  the  claw  of  an  animalcule,  or  some 
such  thing,  by  what  he  calls  the  law  of  natural  selec- 
tion; and  although  these  and  similar  theories  may 
be  held  consistently  with  a  belief  in  a  Divine  Dis- 
poser of  the  spiritual  affairs  of  men,  yet  it  is  too 
true  that  to  many  of  their  advocates  the  order 
of  nature  signifies  nothing  higher  than  self-existing 
matter,  directed  by  inexorable  necessity.  But  no 
cosmogonist  has  been  able  to  go  behind  the  chemi- 
cal elements,  and  until  human  philosophy  can  show 
how  these  forms  of  matter,  with  all  the  marvellous 


198  RELIGION   AND    CHEMISTRY.  [LECT.  VI. 

adjustments  among  their  properties,  have  been 
evolved  out  of  the  "star  dust"  of  the  original 
chaos,  or  out  of  nothing,  and  can  adjust  by  natural 
causes  the  delicate  play  of  forces  in  that  most  fa- 
miliar of  all  phenomena,  a  candle-flame,  it  will  not 
be  able  to  overthrow  the  evidence  of  design  af- 
forded by  this  genial  winter-evening  light ;  and 
the  fact  that  these  would-be  world-makers  explain 
most  satisfactorily  what  men  know  least  about,  is, 
to  say  the  least,  not  in  favor  of  their  theories. 
Yes,  my  friends,  it  is  these  most  familiar  evidences 
of  design  which  are  the  most  impregnable  against 
the  attacks  of  materialism.  It  is  these  household 
altars  that  we  find  always  burning  to  enlighten  our 
dull  understanding,  to  disperse  our  gloomy  doubts, 
and  to  reveal  to  us  the  presence  of  our  God. 

The  delicacy  with  which  the  affinity  of  oxygen 
for  carbon  has  been  adjusted  appears  still  more 
smelting  of  wonderful  when  we  consider  another  of 
the  metais.  fae  uses  Of  ^  force  jn  nature.  The 

useful  metals,  which  may  be  said  to  be  the  tools  of 
civilized  life,  are  seldom  found  in  nature  in  a  pure 
state.  They  generally  occur  combined  with  oxy- 
gen, and  this  compound,  which  is  called  the  ore  of 
the  metal,  is  found  in  beds  or  veins  of  the  rocks, 
where  it  has  been  deposited  through  the  agency 
of  water.  After  the  miner  has  dug  out  the  ore 
from  the  earth,  and  washed  it  free  from  impuri- 
ties, it  is  the  business  of  the  smelter  to  melt  out 
the  pure  metal.  Now  in  this  ore  the  metal  is  com- 
bined with  oxygen,  and  unless  the  smelter  could 


LECT.  VI.]  TESTIMONY   OF   CARBONIC   ACID.  199 

break  this  bond,  the  highest  temperature  of  his 
furnace  would  be  unavailing.  But  the  merciful 
Parent  of  mankind,  when  he  thus  locked  up  these 
his  choicest  gifts,  gave  to  man  a  key  which  would 
unlock  the  treasure-house,  but  left  him  to  find  out 
its  use ;  and  as  in  the  progress  of  humanity  the 
metals  were  required  to  advance  civilization  and 
multiply  the  comforts  of  life,  the  secret  was  discov- 
ered, and  the  treasures  one  by  one  were  brought 
to  light.  The  only  key  needed  was  charcoal.  The 
Creator  has  endowed  carbon  with  a  power  so  strong, 
that  it  readily  overcomes  the  force  by  which  the 
metals  are  united  to  oxygen,  and  by  simply  heat- 
ing the  ore  with  charcoal  the  metal  is  set  free. 
Would  that  I  could  give  you  an  idea  of  the 
strength  of  the  force  which  is  required  to  pro- 
duce this  result.  The  affinity  of  carbon  for  oxy- 
gen is  one  of  the  most  powerful  forces  known  in 
nature,  so  great  as  to  be  immeasurable  by  our  ordi- 
nary human  standards,  and  yet  it  is  this  same  force 
which  produces  that  delicate  result,  the  light  of  a 
candle-flame.  With  such  wonderful  skill  does  God 
wield  these  mighty  agents  of  his  power. 

Consider,  finally,  how  this  power  of  reducing  the 
metallic  ores  has  been  united  in  charcoal  to  those 
other  qualities  which  render  it  so  valuable  as  fuel. 
The  smelter  heats  his  furnace  with  the  self-same 
coals  which  reduce  the  ore.  These  coals  remain 
unchanged  in  contact  with  the  ore  until  they  have 
done  their  work,  and  then  are  converted  into  a  col- 
orless and  harmless  gas,  which  escapes  by  the  chim- 


200  KELIGION   AND    CHEMISTRY.  [LBCT.  VI. 

ney  and  is  wafted  away  by  the  air ;  while,  on  the 
other  hand,  the  melted  metal,  freed  from  its  long 
imprisonment,  flows  out  below  in  glowing  streams, 
ready  to  be  cast  into  thousands  of  useful  forms. 

Keview,  now,  for  a  moment,  the  qualities  of  car- 
bon, and  notice  how  manifold  and  important  are 
the  functions  which  this  element  has  been  ap- 
pointed to  subserve.  It  has  been  made  hard  and 
brilliant,  for  the  glazier's  diamond  and  the  mon- 
arch's crown.  It  has  also  been  made  soft  and  black, 
for  the  artist's  pencil  and  the  printer's  ink.  It  has 
been  made  indestructible  by  atmospheric  agents, 
and  thus  has  preserved  for  us  the  wisdom  of  past 
ages,  and  will  transmit  our  bequests  of  knowledge 
to  those  that  are  to  come.  It  has  been  made  com- 
bustible, and  at  the  same  time  infusible,  in  order  to 
localize  our  fires  and  confine  them  within  their  ap- 
pointed bounds.  It  has  been  made  a  great  reser- 
voir of  heat,  in  order  that  it  might  protect  us  from 
the  winter's  cold,  and  shed  its  enlivening  warmth 
around  the  family  hearth.  It  has  been  endowed 
with  a  strong  affinity  for  oxygen,  in  order  that  it 
might  reduce  the  metallic  ores ;  but  at  the  same 
time  this  affinity  has  been  so  carefully  adjusted 
that  the  carbon  particles  linger  in  the  flame  for  a 
moment  before  passing  into  invisible  gas,  and  thus 
become  a  source  of  light  as  well  as  of  heat.  Last- 
ly, the  product  of  its  combustion  is  a  gas  so  trans- 
parent that  it  does  not  even  cloud  the  atmosphere, 
and  so  bland  that  it  bathes  the  most  delicate  or- 
ganisms without  harm.  What  an  array  of  evidence 


LECT.VI.]  TESTIMONY    OF   CARBONIC   ACID.  201 

have  we  here !  But  this,  my  friends,  is  only  the 
first  stage  of  that  grand  circulation  of  carbon  in 
nature,  which  we  proposed  to  ourselves  as  our  sub- 
ject this  evening.  The  product  of  all  these  vari- 
ous processes  of  combustion  is  carbonic  acid,  and 
let  us  now  follow  this  gas  into  the  atmosphere,  and 
examine  some  of  its  more  familiar  qualities. 

Carbonic  acid  is  so  perfectly  transparent  and  so 
devoid  of  every  active  quality  that  its  presence  can- 
not be  recognized  by  any  of  our  senses,  properties  of 
and  we  must  therefore  call  in  the  aid  of  carbonic  ***- 
experiment  to  make  evident  its  existence.  This  is 
the  reason  why  it  remained  so  long  unknown,  the 
method  we  now  use  for  detecting  its  presence  hav- 
ing been  first  discovered  by  Dr.  Black  only  a  little 
more  than  a  century  ago.  The  method  is  very 
simple.  Carbonic  acid  has  a  great  tendency  to 
combine  with  lime,  and  the  result  of  this  combina- 
tion is  that  familiar  white  solid  called  chalk.  Now 
lime  is  to  a  certain  extent  soluble  in  water,  while 
chalk  is  insoluble  ;  and  hence,  if  lime-water  is  ex- 
posed to  an  atmosphere  containing  carbonic  acid, 
the  formation  of  particles  of  chalk,  rendering  the 
transparent  solution  turbid,  will  indicate  the  pres- 
ence of  the  gas.  Such  a  result  is  actually  obtained 
by  exposing  lime-water  in  a  saucer  for  a  few  days 
to  the  atmosphere,  and  any  one  can  convince  him- 
self by  this  simple  experiment  of  the  existence 
of  carbonic  acid  in  the  medium  around  us,  as  well 
as  in  the  air  which  is  exhaled  from  the  lungs. 


202  RELIGION  AND    CHEMISTRY.  [LECT.  VL 

Indeed,  the  breath  is  so  loaded  with  this  product 
of  combustion  that  lime-water  is  rendered  milky 
by  blowing  into  it  for  only  a  few  minutes.  The 
quantity  of  carbonic  acid  in  the  atmosphere,  how- 
ever, is  relatively  very  small,  not  amounting  to  more 
than  a  few  ten-thousandths  of  its  whole  weight.  It 
enters  to  a  far  greater  extent  into  the  composition 
of  many  rocks.  All  limestones  have  the  same  com- 
position as  chalk,  and  contain  nearly  one  half  of 
their  weight  of  carbonic  acid,  rendered  solid  by  the 
force  of  chemical  affinity.  These  rocks,  indeed,  are 
the  great  reservoirs  of  this  aeriform  compound,  and 
when  you  consider  how  widely  the  limestones  are 
distributed,  underlying  whole  districts  of  country, 
reaching  down  to  unknown  depths,  and  piled  up 
into  vast  mountain-chains,  you  can  form  some  ap- 
preciation of  the  extent  to  which  carbonic-acid  gas 
was  used  in  laying  the  foundations  of  the  globe. 

When  pure,  carbonic-acid  gas  will  instantly  extin- 
guish flame,  and  is  perfectly  irrespirable,  causing 
the  epiglottis  to  close  spasmodically  and  producing 
immediate  death  by  asphyxia.  When  so  far  diluted 
as  to  admit  of  being  received  into  the  lungs,  it  acts 
like  a  narcotic  poison,  causing  drowsiness  and  insen- 
sibility, and  this  even  when  a  candle  will  burn  in 
the  gas.  Hence  the  accidents  which  not  unfre- 
quently  arise  from  heating  a  sleeping-chamber  with 
a  portable  charcoal-furnace,  or  when  from  an  imper- 
fection in  the  flue  the  smoke  of  the  hot-air  furnace 
escapes  into  the  house.  Carbonic  acid  is  not,  how- 
ever, poisonous  in  the  strict  sense  of  that  term.  On 


LECT.VI.]  TESTIMONY    OF   CARBONIC   ACID.  203 

the  contrary,  it  is  always  present  in  the  blood  in 
large  quantities,  and  with  it  bathes  all  the  tissues 
of  the  body.  The  carbonic  acid  results,  as  we  have 
seen,  from  that  slow  combustion  constantly  going 
on  in  the  blood,  by  which  the  animal  heat  is  main- 
tained, and  it  is  an  essential  condition  of  life  that 
this  product  should  be  secreted  from  the  body  as 
fast  as  it  is  formed.  If  the  atmosphere  contains 
more  than  a  small  percentage  of  the  gas,  the  pro- 
cess of  secretion  is  arrested,  and  fatal  results  neces- 
sarily ensue. 

The  density  of  carbonic  acid  is  much  greater 
than  that  of  either  of  the  other  constituents  of  the 
atmosphere,  the  same  volume  weighing  one  half  as 
much  again  as  common  air.  Indeed,  it  is  so  heavy 
that  it  can  be  poured  from  one  vessel  to  another 
like  water,  and  the  immense  volumes  of  carbonic 
acid  which  are  constantly  flowing  from  our  lungs 
and  furnaces  would  cover  the  whole  surface  of  the 
earth  with  their  deadly  vapor,  were  it  not  that  the 
Creator  has  provided,  by  those  simple  laws  of  diffu- 
sion, which  we  studied  in  a  former  Lecture,  that 
this  noxious  gas  should  be  dispersed  as  fast  as  gen- 
erated, and  so  mixed  with  the  great  mass  of  the 
atmosphere  as  to  be  rendered  harmless  by  extreme 
dilution.  The  unfortunate  accidents  which  some- 
times occur  to  persons  who  descend  incautiously 
into  cellars  or  wells,  where  the  carbonic  acid  is 
generated  more  rapidly  than  it  can  be  dissipated, 
constantly  remind  us  that  the  existence  of  animal 
life  on  the  globe  depends  upon  this  beneficent 


204  RELIGION   AND    CHEMISTRY.  [LECT.  VI. 

provision.  The  large  kilns  in  which  lime  is  burnt 
into  quicklime  are  constantly  pouring  out  streams 
of  carbonic-acid  gas,  and  many  a  poor  houseless 
wanderer,  attracted  by  the  heat  of  the  kiln,  has 
lain  down  to  rest  in  the  stream,  and  slept  to  wake 
no  more.  Were  the  force  of  diffusion  much  less 
than  it  is,  we  should  all  be  constantly  exposed  to  a 
similar  fate ;  and  when  we  lie  down  at  night,  it  is 
only  this  guardian  angel  which  prevents  the  deadly 
fumes  of  our  own  fires  from  descending  on  our  beds. 
Carbonic  acid  is  soluble  in  water,  a  given  volume 
of  this  liquid  being  capable  of  absorbing  its  own 
volume  of  the  gas,  irrespective  of  the  temperature 
or  pressure.  We  should  therefore  expect  to  find 
carbonic  acid  in  solution  in  all  water  exposed  to 
the  air,  and  in  fact  a  cubic  foot  of  river,  lake,  or 
ocean  water  generally  contains  a  very  much  greatr 
er  amount  of  this  gas  than  an  equal  volume  of  the 
atmosphere.  Water,  when  holding  carbonic  acid 
in  solution,  has  its  solvent  power  very  greatly  in- 
creased. It  then  dissolves  in  large  quantities  all  the 
varieties  of  limestone,  and  even  granite  rocks  cannot 
wholly  resist  its  action ;  but  these  solutions,  when 
exposed  to  the  air,  gradually  lose  the  carbonic 
acid,  and  with  it  their  solvent  power,  incrusting 
with  calcareous  matter  the  moss,  the  twigs,  or  the 
walls  of  caverns  on  which  the  liquid  may  chance  to 
rest.  It  is  the  solvent  power  of  such  water,  acting 
slowly  through  ages  of  time,  that  has  hollowed  out 
that  immense  cavern  in  the  limestone  strata  of 
Kentucky,  and  it  is  from  the  solution  thus  made 


LECT.  VI.]  TESTIMONY   OF   CARBONIC  ACID.  205 

that  those  stalactitic  ornaments  have  been  formed 
which  add  so  much  to  its  beauty  and  interest.  It 
is  also  this  same  agency  which  in  other  places  has 
deposited  beds  of  calcareous  tufa  over  great  areas, 
and  cemented  together  loose  sands  into  firm  rocks ; 
and  finally,  it  is  from  the  lime  dissolved  in  the 
water  of  the  ocean,  that  the  Crustacea  form  their 
shells  and  the  coral  polypi  build  their  reefs.* 

The  origin  of  carbonic  acid  is  the  same  in  water 
as  in  air.  In  the  water  we  have  not,  of  course,  ac- 
tive combustion ;  but  this,  as  we  have  seen,  is  an  in- 
significant source  of  carbonic  acid  when  compared 
with  the  never-ceasing  functions  of  respiration  and 
decay,  and  these  are  as  active  in  the  rivers,  the 
lakes,  and  the  oceans  as  in  the  atmosphere.  More- 
over, the  purpose  which  the  carbonic  acid  sub- 
serves is  the  same  in  both  cases,  and  this  deserves, 
finally,  our  attentive  study. 

I  have  already  intimated  that  carbonic  acid  is 
one  of  the  few  articles  of  which  the  food  of  plants 
consists.  Let  us  trace,  for  a  moment,  the  history 
of  the  plant.  The  seed  containing  the  germ  is 
placed  in  the  soil.  The  genial  warmth  of  the  sun 
calls  it  into  activity,  and  it  shoots  forth  its  small 
leaflets  into  the  air.  For  a  short  time  the  small 
stock  of  starch  and  similar  nourishment  stored  in 
the  seed  by  a  wise  Providence  serves  for  its  sup- 

*  The  whole  peninsula  of  Florida  has  been  in  great  measure  built 
up  by  these  little  animals  with  the  lime  rock  which  the  waters  of  the 
Mississippi  pour  into  the  Gulf,  and  which  they  have  dissolved  from  the 
lime  deposits  of  our  Western  States. 


206  RELIGION   AND    CHEMISTRY.  [LECT.  VI. 

port ;  but  this  is  soon  exhausted,  and  for  the  future 
the  plant  must  depend  for  its  food  upon  the  soil 
and  upon  the  air.  The  articles  which  compose  its 
diet  are  exceedingly  simple.  They  are  water,  car- 
bonic acid,  and  ammonia,  substances  always  present 
in  the  atmosphere  and  in  every  fertile  soil.  As 
soon  as  the  young  plant  has  expanded  its  green 
leaves  it  absorbs  these  substances,  partly  through 
its  rootlets  from  the  soil,  and  partly  through  its 
leaves  from  the  air.  The  leaf,  a  tissue  of  minute 
organic  cells,  is  the  laboratory  in  which,  from  these 
few  compounds,  are  elaborated  the  different  organs 
of  the  plant.  The  sun's  rays,  acting  on  the  green 
parts  of  the  leaf,  give  to  them  the  power  of  ab- 
sorbing water,  carbonic  acid,  and  ammonia,  and  of 
constructing  from  the  materials  thus  obtained  the 
woody  fibre,  starch,  sugar,  and  other  compounds  of 
which  the  plant  consists.  We  have  analyzed  the 
woody  fibre,  and  we  know  that  it  is  composed  of 
charcoal  and  water.  Nineteen  ounces  of  wood  con- 
tain nine  ounces  of  charcoal  and  ten  ounces  of 
water.  Moreover,  the  amount  of  charcoal  required 
to  make  nineteen  ounces  of  wood  is  contained  in 
thirty-three  ounces  of  carbonic  acid.  If,  then,  we 
add  together  thirty-three  ounces  of  carbonic  acid 
and  ten  ounces  of  water,  and  subtract  from  this 
sum  twenty-four  ounces  of  oxygen,  we  shall  have 
just  the  composition  of  wood.  This  is  what  the 
sun's  light  accomplishes  in  the  leaves  of  the  plant. 
It  decomposes  the  carbonic  acid,  and  unites  its  car- 
bon to  the  elements  of  water  to  form  the  wood. 


LECT.VI.]  TESTIMONY   OF   CARBONIC   ACID.  207 

What  I  have  stated  to  be  true  of  wood  is  equally 
true  of  starch,  gum,  sugar,  and  most  of  the  products 
of  vegetable  life.  All  these,  with  a  few  exceptions, 
which  I  shall  notice  in  the  next  Lecture,  are  pre- 
pared by  the  plant  from  carbonic  acid  and  water, 
under  the  influence  of  the  sun's  light.  Why  it  is 
that  starch  is  deposited  in  the  cells  of  the  potato, 
sugar  in  those  of  the  sugar-cane,  and  gum  and 
woody  fibre,  more  or  less,  in  all  plants,  we  do  not 
know.  These  are  the  mysteries  of  organic  life, 
which  no  science  has  been  able  to  solve.  This 
much,  however,  is  certain.  The  acorn,  buried  in 
the  ground,  grows  into  the  noble  oak.  Of  that 
wide-spreading  tree,  at  least  nine  tenths  consist  of 
charcoal  and  water.  The  water  was  absorbed,  as 
such,  directly  from  the  atmosphere ;  the  charcoal 
was  recovered  from  the  carbonic  acid  decomposed 
by  the  sun's  rays.  Here  is  the  wonderful  fact. 
The  gentle  influences  of  the  sunbeam  have  the 
power  of  reversing  the  process  of -combustion,  of 
overcoming  the  intense  affinity  of  the  fire  element, 
tearing  it  apart  from  the  carbon,  and  restoring  it  to 
the  air.  How  great  this  power  is,  I  have  already 
endeavored  to  illustrate.  I  have  stated  that  the 
affinity  of  oxygen  for  carbon  is  one  of  the  strongest 
affinities  known  to  nature,  immeasurable  by  any 
human  standard.  In  order  to  decompose  carbonic 
acid  in  our  laboratories,  we  are  obliged  to  re- 
sort to  the  most  powerful  chemical  agents,  and  to 
conduct  the  process  in  vessels  composed  of  the 
most  resisting  materials,  under  all  the  violent  mani- 

14 


208  RELIGION   AND    CHEMISTRY.  [LECT.  VI. 

festations  of  light  and  heat,  and  we  then  succeed 
in  liberating  the  carbon  only  by  shutting  up  the 
oxygen  in  a  still  stronger  prison;  but  under  the 
quiet  influences  of  the  sunbeam,  and  in  that  most 
delicate  of  all  structures,  a  vegetable  cell,  the 
chains  which  unite  together  the  two  elements  fall 
ofl^  and  while  the  solid  carbon  is  retained  to  build 
up  the  organic  structure,  the  oxygen  is  allowed  to 
return  to  its  home  in  the  atmosphere.  There  is 
not  in  th,e  whole  range  of  chemistry  a  process  more 
wonderful  than  this.  We  return  to  it  again  and 
again,  with  ever  increasing  wonder  and  admiration, 
amazed  at  the  apparent  inefficiency  of  the  means, 
and  the  stupendous  magnitude  of  the  result.  When 
standing  before  a  grand  conflagration,  witnessing 
the  display  of  mighty  energies  there  in  action,  and 
seeing  the  elements  rushing  into  combination  with 
a  force  which  no  human  agency  can  withstand, 
does  it  seem  as  if  any  power  could  undo  that  work 
of  destruction,  and  rebuild  those  beams  and  rafters 
which  are  disappearing  in  the  flames?  Yet  in  a 
few  years  they  will  be  rebuilt.  This  mighty  force 
will  be  overcome ;  not,  however,  as  we  might  ex- 
pect, amidst  the  convulsion  of  nature,  or  the  dash- 
ing of  the  elements,  but  silently,  in  a  delicate  leaf 
waving  in  the  sunshine.  And  this  is  not  all. 
Those  luminous  waves  which  beat  upon  the  green 
surface  of  the  leaf  are  there  arrested,  and  their 
moving  power  so  completely  absorbed,  that  the  re- 
flected rays  will  not  even  affect  the  exquisitely 
sensitive  plate  of  the  photographer.  But  the  power 


LECT.  VI.]  TESTIMONY   OF   CARBONIC   ACID.  209 

of  the  light  has  not  been  lost,  and  when  the  wood 
is  burnt  and  the  carbon  converted  back  into  car- 
bonic acid,  this  power  reappears  undiminished  in 
the  heat  which  radiates  from  the  burning  embers. 
The  heat,  therefore,  which  the  wood  contains,  and 
which  it  gives  forth  on  burning,  comes  from  the 
sun.  What  a  beautiful  provision  of  Providence 
have  we  here  !  During  the  summer,  when  the 
sun  is  warming  us  with  his  genial  rays,  he  is  also 
laying  up  in  the  growing  wood  vast  stores  of  heat, 
which  will  warm  us  at  the  winter  evening  fireside, 
when  his  rays  have  been  withdrawn. 

But  you  will  tell  me,  it  is  not  wood,  it  is  coal, 
which  is  burning  in  the  grate,  and  you  will  lead 
me,  perhaps,  to  the  mouth  of  some  black  coal-pit, 
and  ask  if  those  dismal  regions  below  ever  saw  the 
sun.  Certainly !  and  it  is  one  of  the  most  remark- 
able revelations  of  modern  science,  that  the  stone- 
like  coal  was  once  alive.  Coal  is  the  remains  of  an 
ancient  vegetation,  which  flourished  on  the  earth 
ages  before  man  first  walked  in  Eden.  The  process 
by  which  it  has  been  formed  and  buried  in  the 
earth  is  well  known.  You  can  see  it  now  forming 
in  many  tropical  swamps.  There  you  will  find  a 
vast  mass  of  vegetable  matter,  the  result  of  a  rank 
vegetation,  gradually  decaying  under  water.  The 
land  is  gradually  sinking,  and  as  this  bed  of  peat 
sinks  with  it,  it  becomes  covered  with  mud  and 
sand,  which  numerous  streams  are  constantly  wash- 
ing into  the  swamp.  This  goes  on  year  after  year, 
century  after  century,  age  after  age,  until  the  bed 


210  RELIGION   AND    CHEMISTRY.  [LECT.  VI. 

is  buried  hundreds  of  feet  beneath  the  surface.  In 
the  mean  time  the  vegetable  tissues  undergo  a  sort 
of  internal  combustion,  similar  to  that  which  takes 
place  in  a  charcoal  mound.  Wood  consists,  you 
will  remember,  of  charcoal  and  the  elements  of 
water.  The  oxygen  which  it  contains  reacts  on 
the  carbon  and  hydrogen.  Carbonic  acid  and 
water  are  formed,  which  escape,  while  the  rest  of 
the  hydrogen  and  carbon  unite  together  to  form 
the  coal.  The  reaction  is  a  true  process  of  combus- 
tion, and  the  heat  thus  evolved  aids  the  chemical 
change,  and  gives  to  the  coal  its  baked  appearance. 
This  change  it  requires  long  ages  to  complete. 
Millions  and  millions  of  times  has  the  earth  re- 
peated its  annual  revolution  around  the  sun,  and 
the  whole  external  appearance  of  the  globe  has 
changed  since  those  mighty  forests  grew,  which 
have  been  petrified  in  the  coal.  But  though  such 
long  intervals  have  elapsed,  their  history  has  not 
been  lost.  It  has  been  written  on  the  rocks,  the 
mighty  monuments  of  past  ages.  The  geologists 
have  read  it,  and  we  know  with  as  much  certainty 
the  form  of  the  leaves  and  the  structure  of  the 
stems  of  those  ancient  trees,  as  we  do  those  of  the 
oak  or  the  chestnut.  We  know  also  that  every 
atom  of  coal  which  now  lies  buried  hundreds  of 
feet  beneath  the  surface  was  once  a  part  of  the  at- 
mosphere, and  that  the  heat  which  it  evolves  by 
burning  was  received  from  the  sun,  when  the  car- 
bonic acid  was  decomposed  by  the  light  in  the 
leaves  of  the  ancient  trees.  Consider  for  a  moment 


LECT.  VI.]  TESTIMONY   OF   CARBONIC   ACID.  211 

of  what  immense  value  to  man  are  those  beds  of 
coal.  Without  them  modern  civilization  would 
have  been  impossible.  Eemember  that  since  the 
dawn  of  creation  the  sun  has  been  employed  in  ac- 
cumulating these  vast  stores  of  force,  and  thus  pre- 
paring the  globe  for  civilized  man.  We  may  ad- 
mire the  genius  of  a  Papin  and  a  Watt,  who  have 
told  us  how  to  use  this  force,  and  who  have  thus 
covered  the  ocean  with  steamships,  and  the  land 
with  railroads;  but  let  us  not  forget  that  infi- 
nitely greater  wisdom  which  saw  the  end  from  the 
beginning,  and  before  the  mountains  were  brought 
forth  or  ever  the  continents  were  formed,  laid  up 
the  beds  of  coal  in  the  early  strata,  and  preserved 
them  through  the  long  ages  of  geological  time 
until  the  earth  was  fitted  to  become  the  abode  of 
man. 

I  have  now  glanced  at  some  of  the  distinctive 
features  of  the  great  circulation  of  carbon  in  nature, 
and  have  endeavored  to  show  that  the  sun's  rays 
are  the  prime  moving  power  of  the  whole.  I  trust 
that  you  have  been  impressed  with  the  grandeur 
of  its  cycles,  the  delicacy  of  its  adjustments,  and 
the  mighty  power  of  that  mysterious  influence  by 
which  it  is  sustained ;  but  above  all  may  it  be 
my  privilege  to  have  succeeded  in  making  clear 
to  your  intellectual  vision  those  marks  of  wisdom 
and  of  power  which  have  been  so  visibly  stamped 
upon  this  Divine  economy. 


LECTUEE    VII. 

TESTIMONY   OF  NITROGEN. 

IN  order  to  complete  my  very  imperfect  sketch  of 
the  wonderful  adaptations  which  the  various  quali- 
ties and  functions  of  our  atmosphere  present,  I  wish 
in  my  Lecture  this  evening  to  examine  with  you  the 
properties  of  nitrogen,  that  aeriform  element  which 
is  its  chief  constituent,  making  up  no  less  than  four 
fifths  of  its  entire  mass.  This  gas,  although  so 
seemingly  inert,  discharges  functions  no  less  impor- 
tant than  those  of  oxygen  to  the  well-being  of  man. 
Nitrogen  not  It  is  not,  however,  like  oxygen,  an  ele- 
wiaeiydiffused.  ment  ^flely  distributed  in  nature,  and  en- 
tering as  a  chief  constituent  into  the  composition 
of  the  globe.  The  atmosphere  is  the  only  great 
reservoir  of  nitrogen,  and  to  this  and  to  the  bodies 
of  organized  beings  its  presence  is  almost  exclu- 
sively confined.  It  seems  to  be  the  essential  ele- 
ment of  all  the  higher  forms  of  corporeal  vitality, 
and  it  is  frequently  called  the  zoogen,  or  life-gener- 
ator. By  some  mysterious  process  it  is  constantly 
being  withdrawn  from  the  atmosphere,  and  entering 
into  the  composition  of  the  numberless  living  forms 
which  clothe  the  earth  with  verdure  and  crowd  it 
with  animal  life ;  but  these  forms  soon  pass  away, 
and  by  the  inevitable  process  of  decay  the  nitrogen 


LECT.  VII.]  TESTIMONY   OF   NITROGEN.  213 

is  restored  to  the  great  reservoir  from  which  it 
was  originally  withdrawn.  Science  has  not  as  yet 
been  able  to  follow  all  the  steps  of  this  remarka- 
ble process,  but,  nevertheless,  enough  is  known  to 
show  that  the  properties  of  nitrogen  have  been 
most  admirably  adapted  to  the  numerous  important 
ends  which  it  has  been  appointed  to  subserve. 

Nitrogen  is  then  peculiarly  the  element  of  the 
atmosphere.  It  not  only  constitutes  the  greater 
part  of  the  aerial  ocean,  but  it  exists  there  in  a  per- 
fectly free  and  uncombined  condition,  and  —  with 
the  self-limiting  exceptions  just  noticed  —  is  found 
nowhere  else.  Occupying  so  important  a  place 
in  the  scheme  of  creation,  we  should  nat- 

.  .  Negative 

urally  expect  to  find  in  nitrogen  a  sub-  properties  of 
stance  full  of  the  highest  interest.  Yet 
nothing  could  be  less  inviting  than  its  external 
properties.  A  permanent  gas,  even  at  the  lowest 
temperatures,  without  color  or  odor,  it  is  entirely 
devoid  of  every  active  property.  It  will  extinguish 
a  candle  immersed  in  it,  and  will  not  sustain  ani- 
mal life  :  but  these  are  merely  negative  qualities ; 
for  animals  cannot  live  in  an  atmosphere  of  nitro- 
gen, solely  because  it  does  not  contain  oxygen,  and 
it  will  not  support  combustion  because  it  is  not  en- 
dowed with  active  affinities.  And  in  all  other  out- 
ward aspects  nitrogen  is  equally  inert.  It  exerts 
no  action  whatever  upon  the  most  delicate  chem- 
ical compounds,  and  with  a  few  unimportant  excep- 
tions will  not  enter  into  direct  combination  with 
any  of  the  chemical  elements.  Consider  also  the 


214  RELIGION   AND    CHEMISTRY.  [LECT.  VH. 

nitrogen  as  it  exists  in  the  atmosphere.  Although 
in  immediate  contact  with  the  most  violent  of  the 
elements,  and  exposed  to  its  action  when  in  its 
fiercest  state,  under  the  varying  influences  of  light, 
heat,  and  electricity,  yet  no  combination  between 
the  two  results,  except  to  a  very  limited  extent, 
and  under  peculiarly  oblique  conditions.  Through 
an  ordinary  iron  blast-furnace  there  pass  in  the 
course  of  a  single  day  many  tons  of  this  mixture 
of  nitrogen  and  oxygen  called  air.  The  oxygen,  as 
we  know,  causes  the  most  violent  chemical  action ; 
but  although  the  nitrogen  is  brought  into  contact 
with  the  same  intensely  heated  coal  and  iron,  no 
combination,  at  least  of  any  importance,  ensues. 

Shall  we  then  conclude  that  nitrogen  is  entirely 
unendowed  with  chemical  affections,  —  that  it  is  ca- 
pable of  forming  no  chemical  compounds,  and  of 
producing  no  powerful  effects,  —  that  it  is,  in  fine,  a 
mere  dead  weight  in  the  atmosphere,  placed  there, 
for  the  want  of  something  better,  to  fill  up 

Compounds 

of  nitrogen  the  void  and  to  give  the  required  den- 
indict0^  y  sity,  as  a  ship  is  frequently  loaded  with 


ballast  when  there  is  a  lack  of  freight  ? 
Such  is  the  conclusion  to  which  the  appearances 
would  naturally  lead,  and  such  is  the  conclusion  at 
which  the  chemists  arrived  in  the  early  stages 
of  their  inquiry.  Yet  no  conclusion  could  be 
more  at  variance  with  actual  facts ;  for  so  far  is 
it  from  true  that  nitrogen  is  the  uninteresting 
substance  which  these  negative  qualities  would 
seem  to  indicate,  that  there  are  but  few  elements 


LECT.VIL]  TESTIMONY   OF  NITROGEN.  215 

which  form  a  larger  number  of  compounds,  or 
which  are  endowed  with  more  varied  powers  when 
the  necessary  conditions  of  combination  are  ful- 
filled. Nitrogen  can  be  made  to  unite  with  the 
other  elements  only  by  indirect  and  circuitous  pro- 
cesses. It  is  one  of  its  most  distinctive  qualities 
to  avoid  direct  combination ;  but  when  the  neces- 
sary conditions  are  present,  it  surprises  us  by  the 
readiness  with  which  it  combines,  and  by  the  great 
variety  and  remarkable  character  of  the  result- 
ing compounds.  When  we  should  least  expect  it, 
we  find,  not  single  compounds,  but  whole  classes, 
springing  into  existence,  which,  while  they  often 
defy  our  investigations  by  their  protean  charac- 
ter, excite  our  admiration  by  the  simplicity  of 
their  constitution  and  by  the  beauty  of  the  plan 
according  to  which  they  have  all  been  fashioned. 
The  points,  then,  which  especially  characterize  ni- 
trogen, and  in  which  the  evidences  of  design  in  its 
constitution  are  to  be  traced,  are,  first,  its  unexam- 
pled inertness  when  in  a  free  condition ;  secondly, 
the  variety  and  remarkable  nature  of  its  com- 
pounds ;  thirdly,  the  peculiarly  oblique  processes 
by  which  all  its  compounds  are  formed ;  and,  lastly, 
their  very  great  instability. 

Nitrogen  may  be  very  appropriately  termed  the 
ballast  of  the  atmosphere,  and  this  is  undoubtedly 
the  most  obvious  of  its  functions.  Air, 

.  '    Nitrogen  the 

you  will  remember,  is  not  in  any  proper  bailor  the 

sense  of  the  term  a   distinct   substance. 

It  is  a  mixture   of  several  substances,  or  rather 


216  RELIGION   AND    CHEMISTRY.  [LECT.  VII. 

there  coexist  around  the  globe  at  least  three  differ- 
ent atmospheres,  one  of  nitrogen,  one  of  oxygen, 
one  of  aqueous  vapor,  and  perhaps  we  should  add, 
as  a  fourth,  one  of  carbonic  acid,  each  with  its  own 
peculiar  characteristics,  and  so  entirely  distinct  that 
it  would  retain  all  its  essential  properties  were  the 
rest  removed.  Again,  when  studying  in  our  fifth 
Lecture  the  general  features  of  the  great  aqueous 
circulation  on  the  earth,  we  discovered  that  the 
whole  plan  turns  on  the  fact  that  the  atmosphere 
of  aqueous  vapor  is  mixed  with  a  large  mass  of 
other  aeriform  matter,  which  moderates  all  atmos- 
pheric changes  and  mitigates  the 'violence  of  their 
effects.  It  also  appeared  in  the  third  Lecture  that 
the  atmosphere  of  oxygen  has  been  subjected  to 
a  similar  restraint,  and  that  the  aroused  energies 
of  this  terrible  destroyer  are  most  carefully  tem- 
pered by  great  dilution.  As  the  atmosphere  is 
constituted,  the  oxygen  cannot  reach  the  burning 
combustible  without  carrying  with  it  the  whole 
mass  of  the  surrounding  air ;  but  if  this  mass  of  aeri- 
form matter  were  not  present,  the  devouring  ele- 
ment would  rush  upon  its  prey  with  a  fury  which 
nothing  could  withstand,  and  iron  *  would  burn  as 
readily  as  straw.  Moreover,  in  several  other  con- 
nections we  have  shown  that  it  is  an  essential  condi- 
tion in  the  scheme  of  terrestrial  nature  that  the  air 
should  have  its  actual  density.  See  now  how  beau- 
tifully all  the  conditions  are  fulfilled  in  the  atmos- 

*  An  iron  watch-spring  burns  with  the  greatest  readiness  in  a  jar  of 
pure  oxygen  gas. 


LECT.  VH.]  TESTIMONY   OF  NITKOGEN.  217 

phere.  The  proportion  of  oxygen  has  been  most 
carefully  adjusted  to  the  necessities  of  animal  life, 
and  made  so  small  that  the  violence  of  the  fire-ele- 
ment may  be  restrained  within  due  limits.  The 
amounts  of  aqueous  vapor  and  of  carbonic  acid 
have  in  like  manner  each  been  accurately  adjusted 
to  the  purposes  which  it  was  appointed  to  sub- 
serve, and  then,  in  order  to  make  up  the  required 
density,  a  large  mass  of  a  perfectly  inert  gas  has 
been  added.  Thus  in  the  very  inertness  of  nitro- 
gen we  find  the  most  obvious  evidence  of  adapta- 
tion. Its  negative  qualities  are  precisely  those  re- 
quired in  a  substance  which  is  designed  to  act  as  so 
much  dead  material,  adding  to  the  density  of  the 
atmosphere  without  interfering  with  the  functions 
of  its  active  agents. 

Consider,  also,  how  very  greatly  this  evidence 
of  design  is  enhanced  by  the  fact  that  nitrogen  is 
found  only  in  the  atmosphere  and  in  the 

J  m  .  .  .  Evidence  of 

bodies  of  organized  beings,  into  which  it  special  adapta- 
has  been  temporarily  withdrawn.  It  is 
not,  like  oxygen,  carbonic  acid,  or  water,  a  main 
constituent  of  the  globe,  and  cannot  therefore  be 
regarded,  as  the  fatalists  would  have  us  believe,  as 
so  much  material  left  over  after  the  solid  globe  had 
been  condensed  by  the  molecular  forces  from  a 
chaotic  nebula.  Nitrogen  is  not  only  exactly 
adapted  to  the  functions  it  subserves  in  the  at- 
mosphere, but  moreover  these  are  its  only  uses, 
and  I  cannot  see  how  it  is  possible  to  resist  the  con- 
clusion that  it  was  especially  designed  for  the  place 


218  KELIGION   AND    CHEMISTRY.  [LECT.  VII. 

it  fills.  That  you  may  appreciate  the  strength  of 
this  evidence,  let  me  illustrate  the  subject  by  an 
example  from  common  life,  which  will  be  more  to 
our  purpose  than  a  philosophical  analysis  of  the 
argument  itself. 

It  does  not  follow  that  the  square  granite  blocks 
which  form  the  greater  part  of  the  front  of  yonder 
magnificent  warehouse,  however  well  adjusted  they 
may  be,  were  actually  cut  with  reference  to  this 
building,  although  the  strong  presumption  is  that 
they  were.  Nor  does  it  follow  that  those  highly 
ornamented  window-caps  and  that  elaborate  cornice 
were  originally  designed  for  this  particular  edifice, 
although  the  presumption  that  such  was  the  case  is 
still  stronger  than  before.  Nay,  more,  it  is  not  even 
absolutely  certain  that  those  skilfully  carved  orna- 
ments which  adorn  the  front,  and  are  built  into  the 
walls,  were  originally  intended  to  be  placed  where 
they  are,  although  to  doubt  this  conclusion  would 
be  the  extreme  of  incredulity.  I  admit,  it  is  barely 
possible  that  they  were  originally  made  for  another 
building,  rejected,  perhaps  for  some  defect,  and 
afterwards  put  up  here.  But  I  will  show  you 
whore  there  is  an  evidence  of  design  in  the  building- 
material  of  this  warehouse  which  you  will  be  forced 
to  accept  It  is  not  conspicuous,  and  might  be 
overlooked.  Just  here  at  the  corner  of  the  build- 
ing there  is  a  very  peculiarly  shaped  block  of  stone. 
You  never  saw  one  like  it  before.  This  extraordi- 
nary shape  was  required  by  the  peculiar  form  of 
the  building  lot  and  the  position  of  the  walls  on 


vn.]  TESTIMONY   OF   NITROGEN.  219 

:he  adjoining  estate.  The  sides  of  the  lot  are  not 
perpendicular  to  the  front,  and  the  block  has  been 
:ut  to  the  precise  angle  of  the  bevel,  and  at  the 
same  time  exactly  fits  the  adjacent  walls.  The 
conclusion  that  this  block  was  designed  for  that 
place  is  irresistible.  No  sane  mind  would  doubt  it 
for  a  moment.  I  do  not  say  there  is  not  one 
chance  in  many  millions,  estimated  on  the  doctrine 
of  probabilities,  that  a  block  of  this  exact  size  and 
shape  might  have  been  found  among  the  refuse 
stock  of  the  stone-cutter's  yards  ;  but  I  do  say,  that, 
in  the  absence  of  absolute  proof  to  the  contrary,  the  cer- 
tainty that  this  granite  block  was  wrought  with 
reference  to  the  place  it  fills,  and  that  the  exact 
correspondence  of  its  dimension  and  angles  was  the 
result  of  measurement,  is  as  great  as  it  is  possible 
to  attain  by  any  process  of  reasoning  short  of  a 
mathematical  demonstration ;  moreover,  it  is  as 
great  as  can  be  obtained  in  physical  science,  or 
in  any  department  of  human  knowledge  one  step 
removed  from  the  facts  of  consciousness  or  of  ob- 
servation. 

The  evidence  that  nitrogen  was  designed  for 
the  place  which  it  fills  in  the  atmosphere  is  vastly 
stronger  than  this.  The  force  of  the  argument  in 
the  illustration  just  cited  evidently  increases  very 
rapidly,  the  more  singular  the  shape  of  the  granite 
block,  and  the  more  accurately  its  form  has  been 
adjusted  to  the  place  it  fills.  Now  nitrogen  is  as 
unique  among  the  chemical  elements,  as  water  is 
among  the  compounds.  Its  external  properties  are 


220  RELIGION  AND    CHEMISTRY.  [LECT.  VII. 

so  entirely  different  from  those  even  of  the  class  of 
elements  to  which  it  belongs,  that  chemists  can 
hardly  believe  that  it  is  a  simple  substance,  and  for 
the  last  fifty  years  have  been  vainly  attempting  to 
decompose  it;  but  it  has  resisted  all  their  efforts, 
and  the  more  intimately  they  have  become  ac- 
quainted with  its  properties,  the  more  singular  and 
exceptional  it  has  appeared.  At  the  same  time, 
while  presenting  these  remarkable  anomalies,  nitro- 
gen has  been  fitted  to  the  unique  place  which  it 
fills  in  the  scheme  of  creation,  with  a  nicety  and 
precision  which  it  is  as  much  beyond  our  powers  of 
thought  to  conceive,  as  it  is  beyond  my  feeble  lan- 
guage to  describe.  It  is  not  only  that  one  or  two 
of  the  corners  of  this  block  of  nature's  edifice  have 
been  bevelled  to  an  exact  angle,  but  it  has  been 
adjusted  at  every  point  to  the  ten  thousand  con- 
ditions of  that  complex  structure  which  I  have 
been  describing,  but  how  imperfectly !  during  this 
course  of  Lectures,  with  a  skill  immeasurably 
beyond  all  human  art,  and  with  an  intelligence 
which  "  looketh  to  the  ends  of  the  earth  and  seeth 
under  the  whole  heaven."  If  this  is  so,  —  and  you 
will  find  that  my  guarded  expressions  fall  far  short 
of  the  truth,  —  why  not  use  in  these  matters  of 
faith  the  same  common  sense  which  we  apply  with 
so  much  success  in  common  life,  and  which  in  our 
daily  intercourse  it  would  be  nothing  short  of  mad- 
ness to  disregard  ?  We  do  not  hesitate  to  trust  the 
skill  and  honesty  of  a  fellow-man,  whom  we  not 
only  have  never  seen,  but  even  as  to  whose  char- 


LECT.VH.]  TESTIMONY   OF   NITROGEN.  221 

acter  our  sole  evidence  is  the  most  indefinite  testi- 
mony. Why,  then,  not  accept  the  precious  and 
comforting  truths  of  religion,  and  repose  equal  faith 
in  the  providence  of  your  Heavenly  Father,  on  evi- 
dence which,  you  must  admit,  is  ten  thousand  fold 
stronger,  and  when  you  have  everything  to  gain, 
and  nothing  to  lose  ?  Is  it  said,  there  is  still  room 
for  doubt  ?  Of  course  there  is.  God  be  thanked  ! 
there  is  no  relation  in  life  in  which  there  is  not 
doubt.  Were  there  no  doubt,  there  would  be  no 
faith,  no  trust,  no  confidence,  no  love ;  the  heart 
would  be  absorbed  in  the  intellect,  religion  would 
become  an  axiom,  and  morality  a  formula  of  math- 
ematics. Use  but  one  half  of  the  observation,  one 
half  of  the  intelligence,  which  are  never  at  fault 
in  the  business  of  life,  and  these  marks  of  the  Crea- 
tor's wisdom  and  providence  which  lie  all  around 
us  will  become  as  evident  as  the  sun.  Act  on 
this  evidence,  and  the  door  of  grace  will  be  opened, 
new  light  will  stream  into  the  soul,  and  all  nature 
will  be  seen  radiant  with  a  Father's  love. 

All  this  striking  evidence  of  design  and  adapta- 
tion we  have  discovered  in  the  most  obvious  of  the 
attributes  of  nitrogen,  —  in  those  merely  compounds  of 
negative  qualities  in  virtue  of  which  it  nitr°sen- 
increases  the  density  of  the  atmosphere  without 
interfering  with  the  functions  of  the  active  con- 
stituents. It  would  not,  however,  be  in  accordance 
with  that  economy  of  resources  which  we  find 
everywhere  in  nature,  that  the  uses  of  nitrogen 
should  be  limited  to  this  single  object;  and  after 


222  EELIGION   AND    CHEMISTRY.  [LECT.  vn. 

what  we  have  already  seen  to  be  true  in  the  case 
of  oxygen,  we  shall  not  be  surprised  to  find  this 
singular  element  suddenly  changing  its  character 
and  appearing  in  a  new  condition.  The  second 
point,  as  you  will  remember,  which  I  am  to  illus- 
trate in  regard  to  nitrogen,  is  the  variety  and  re- 
markable nature  of  its  compounds,  as  well  as  the 
singularly  oblique  processes  by  which  they  are 
formed ;  and,  having  examined  the  marks  of  design 
it  bears  in  its  first  manifestation,  let  us  now  study 
the  no  less  impressive  evidence  presented  by  the 
second.  It  would  be  entirely  out  of  place  in  a 
course  of  Lectures  like  the  present,  to  describe  in 
detail  any  of  the  countless  nitrogenized  compounds 
which  are  known  to  chemistry,  and  it  would  re- 
quire a  long  course  of  Lectures  merely  to  illustrate 
the  characteristic  features  of  the  great  classes  into 
which  they  may  be  subdivided.  I  shall  be  able 
only  to  glance  at  a  few  general  facts  which  illus- 
trate the  point  now  under  discussion,  and  also  the 
part  which  nitrogen  plays  in  organic  nature. 

Although  nitrogen  presents  such  an  indifferent 

exterior  towards  the  oxygen  of  the  atmosphere,  it 

can,  nevertheless,  be  made  to  combine  with  it  by 

resorting  to  certain  oblique  processes,  and  there 

may  be  thus  formed  no  less  than  five  dif- 

Nitric  acid.  _  .       _        ... 

ferent  compounds.     Every  one  is  familiar, 
with  that  highly  corrosive  liquid  called  nitric  acid, 
and  this  is  one  of  the  compounds  in  question.     Un- 
der certain  conditions  it  is  formed  by  the  union  of 
the  oxygen  and  nitrogen  which  are  mixed  together 


LKCT.  VIL]  TESTIMONY   OF   NITROGEN.  223 

in  the  air.  The  only  essential  difference  between 
the  bland  atmospheric  air  and  this  highly  active 
chemical  agent  consists  in  the  fact  that  in  air  the 
elements  are  only  mixed  together,  while  in  the 
acid  they  are  chemically  combined.  Were  nitro- 
gen to  be  suddenly  endowed  with  the  active  affini- 
ties which  from  its  position  among  the  chemical 
elements  we  might  naturally  expect  it  to  possess, 
then  a  large  part  of  the  atmosphere  would  be  show- 
ered down  upon  the  earth  in  floods  of  nitric  acid. 
It  is  only  the  unexampled  inertness  of  nitrogen 
which  prevents  the  formation  of  this  deadly  com- 
pound. But  although  so  corrosive  when  pure,  ni- 
tric acid  when  immensely  diluted  is  one  of  the  few 
materials  which  nourish  and  sustain  vegetable  life, 
and  therefore  provision  has  been  made  that  it 
should  be  formed  in  the  atmosphere,  but  only  un- 
der very  restricted  conditions  and  to  a  very  limited 
extent.  When  electrical  sparks  are  passed  through 
a  confined  quantity  of  air,  in  the  presence  of  some 
alkaline  substance,  such  as  potash,  soda,  or  lime,  a 
very  partial  combination  takes  place  between  the 
two  elements,  and  an  infinitesimal  quantity  of  nitric 
acid  is  formed.  So  also  when  organic  matter  decays 
in  the  presence  of  these  same  alkalies,  a  similar  com- 
bination, although  to  a  very  slight  extent,  results. 
Nitric  acid  is  endowed  with  such  violent  affinities 
that  it  does  not  remain  in  a  free  state.  It  at  once 
enters  into  combination  with  the  alkalies,  forming  a 
class  of  salts,  of  which  saltpetre  is  the  best  known 
example,  and  from  those  salts  the  common  nitric 

15 


224  RELIGION   AND    CHEMISTRY.  [LECT.  Vn. 

acid  is  extracted  for  the  uses  of  the  arts.  Nitrogen, 
you  will  notice,  acts  here  very  much  like  a  self- 
willed  child.  All  the  powers  of  nature  cannot  com- 
pel it  to  combine  directly  with  oxygen  ;  but  if  you 
offer  to  it  these  alkalies  as  an  inducement,  and  make 
your  approaches  sufficiently  indirect,  you  can  coax 
it  to  combine,  and  nitric  acid  is  then  formed.  We 
do  not  understand  how  the  peculiar  conditions  just 
mentioned  conspire  to  produce  the  result ;  but  the 
whole  phenomenon  seems  to  be  mysteriously  con- 
nected with  ozonized  oxygen,  and  is  undoubtedly 
another  phase  of  that  obscure  subject,  attotropism,  to 
which  we  alluded  in  a  previous  Lecture.  See  now 
how  beautifully  this  attribute  of  nitrogen  has  been 
adapted  to  the  conditions  of  vegetable  life,  and 
made  the  means  by  which  the  plant  is  furnished 
with  one  of  the  articles  of  its  food.  Every  dis- 
charge of  lightning  is  accompanied  by  a  partial 
combination  of  the  elements  of  the  atmosphere,  and 
the  nitric  acid  which  is  thus  formed  and  washed 
down  by  the  rain-water  serves  to  fertilize  the  soil 
and  bring  the  growing  corn  to  maturity.  So  in 
like  manner,  when  life  is  extinct,  and  the  organized 
forms  are  resolved  into  their  original  elements,  the 
very  process  of  decay  causes  a  similar  combinati6n, 
and  thus  sweetens  the  flowers  which  spring  from 
the  grave. 

But  not  only  does  nitrogen  combine  with  oxy- 
gen. It  unites  also  with  hydrogen,  that  element 
which  is  the  very  antithesis  of  oxygen,  and  forms 
a  most  remarkable  compound  called  ammonia. 


LECT.  VH.]  TESTIMONY   OF   NITROGEN.  225 

This  substance  is  the  very  reverse  of  nitric  acid  in 
all  its  chemical  relations,  but  like  nitric  acid  it  is  a 
highly  active  and  caustic  agent.  I  need 
not  dwell  upon  this  fact ;  for  the  common 
smelling-bottle  has  made  every  one  familiar  with 
this  pungent  substance.  Nitrogen  manifests  the 
same  indifference  towards  hydrogen  that  it  does 
towards  oxygen,  and  the  two  elements  can  be  made 
to  unite  only  by  indirect  processes,  which  are  not 
well  understood.  The  most  important  of  these  is 
the  process  of  decay.  This  destructive  change  in 
all  the  higher  forms  of  organized  beings  is  attended 
with  the  formation  of  ammonia,  and  the  same  nitro- 
genized  compound  is  a  uniform  result  of  the  nor- 
mal functions  of  animal  life.  You  will  not,  there- 
fore, be  surprised  to  learn  that  traces  of  ammonia, 
as  of  nitric  acid,  are  found  in  the  atmosphere  and 
in  all  rain-water.  Indeed,  it  is  generally  supposed 
that  the  two  are  in  combination,  forming  a  salt 
called  nitrate  of  ammonia,  but  the  amount  present 
is  at  best  very  small. 

Ammonia  is  thought  by  many  to  be  a  more  im- 
portant article  of  vegetable  diet  than  nitric  acid ; 
but  our  knowledge  of  agricultural  chemistry  is  very 
imperfect,  and  chemists  are  not  agreed  on  many 
of  the  most  fundamental  points.*  Still,  as  I  have 

*  Since  these  Lectures  were  written,  it  has  been  stated  by  several 
investigators  that  the  chief  nitrogen  compound  in  the  atmosphere  and 
in  rain-water  is  nitrite  of  ammonia,  which  differs  from  the  nitrate  of  am- 
monia mentioned  above  only  in  containing  a  smaller  proportion  of  oxy- 
gen. Whether  the  last  is  also  normally  present  does  not  yet  appear,  and 
to  what  extent  the  one  or  the  other  may  be  concerned  in  the  processes  of 


226  RELIGION   AND    CHEMISTRY.  [LECT.  VII. 

before  stated,  nitrogen  is  an  essential  element  of 
all  the  higher  forms  of  corporeal  vitality,  and  com- 
pounds like  those  we  have  been  considering  are 
the  appointed  channels  by  which  it  is  introduced 
into  the  organization  of  the  plant.  Had  these  com- 
pounds been  allowed  to  form  to  any  extent  in  the 
atmosphere,  they  would  soon  have  rendered  the 
globe  uninhabitable.  It  was  therefore  essential 
that  nitrogen  should  be  endowed  with  that  unex- 
ampled inertness  which  it  manifests  in  its  gaseous 
state.  But  had  not  at  the  same  time  a  power  of 
combination,  under  certain  restricted  conditions, 
been  granted,  this  chemical  element  would  not 
only  have  been  an  isolated  phenomenon  in  nature, 
an  exception  to  its  general  laws,  but  its  usefulness 
would  have  been  restricted  to  the  least  remarkable 
of  its  functions.  Unlike  the  results  of  human  skill, 
this  creation  of  Divine  wisdom  has  been  adapted 

vegetable  growth,  has  not  been  determined.  From  one  point  of  view, 
nitrite  of  ammonia  may  be  regarded  as  composed  of  nitrogen  gas  and 
water,  and  some  chemists  believe  that  it  is  formed  by  the  direct  union 
of  these  two  substances,  and  that  this  union  is  favored  by  the  processes 
of  evaporation,  combustion,  and  decay,  which  are  constantly  going  on  in 
the  atmosphere.  This  theory  is  certainly  supported  by  many  facts,  and 
those  who  hold  it  generally  believe  that  nitrite  of  ammonia  is  the  chief, 
if  not  the  sole,  source  from  which  the  plants  derive  their  supply  of  nitro- 
gen, while  others  attach  only  a  secondary  importance  to  the  recent  ex- 
periments. If  the  theory  is  correct,  the  formation  of  nitrate  of  ammo- 
nia—the presence  of  which  in  surface-water,  and  in  the  soil,  under 
certain  conditions,  is  beyond  doubt  —  would  be  the  natural  result  of 
the  subsequent  union  of  nitrite  of  ammonia  (formed  as  just  described) 
with  the  oxygen  of  the  air ;  but,  as  intimated  above,  the  whole  subject 
is  still  very  obscure,  and  from  any  experiments  yet  made  we  should  not 
be  justified  in  drawing  definite  conclusions. 


LECT.VH.]  TESTIMONY   OP  NITROGEN.  227 

to  the  most  varied  and  apparently  incompatible 
ends ;  and  while  in  the  atmosphere  it  is  a  mere  dead 
weight,  it  is  also  the  most  plastic  of  the  elements,  is 
capable  of  entering  into  the  most  complex  relations, 
and  thus  serves  as  the  peculiar  substratum  of  all 
the  higher  forms  of  organized  being. 

The  last  point  I  am  to  illustrate  in  regard  to 
nitrogen  is  perhaps  the  most  characteristic  of  its 
features,  and  it  is  one  on  which  its  rela- 

Instability  of 

tions  in  the  scheme  of  organized  nature  nitrogenized 
very  greatly  depend.  All  the  compounds  compou 
of  nitrogen  are  very  unstable,  and  the  slightest 
force  is  generally  sufficient  to  overpower  the  deli- 
cate affinities  by  which  the  elements  are  held  to- 
gether, when  the  nitrogen  at  once  returns  to  its 
home  in  the  atmosphere.  Although  this  inert  ele- 
ment may  be  coaxed  into  combination,  it  never 
forms  strong  compounds.  Its  affinities,  although 
so  varied,  are  at  best  very  feeble  and  delicate.  It 
is  always  a  weak  timber  in  a  chemical  structure, 
and  when  this  timber  breaks,  as  it  certainly  will, 
sooner  or  later,  the  whole  falls.  You  will  need  no 
further  illustration  of  this  fact  than  to  be  told  that 
gunpowder,  percussion-powder,  and  gun-cotton  are 
all  nitrogenized  compounds,  and  owe  their  well- 
known  properties  to  the  weak  affinities  of  this  ele- 
ment. Nitric  acid  is  only  a  little  more  stable  than 
these  explosive  agents,  and  ammonia,  although  one 
of  the  most  permanent  of  nitrogenized  compounds, 
is  still  very  easily  decomposed.  Passing  next  to 
organized  substances,  we  find  this  distinguishing 


228  RELIGION   AND    CHEMISTRY.  [LECT.  VH. 

character  still  more  conspicuous.  As  we  have 
already  seen,  it  is  always  the  nitrogenized  com- 
pounds which  start  the  decay  in  vegetable  or  ani- 
mal structures ;  and  thus  the  great  characteristic 
feature  of  all  organized  matter,  its  proneness  to 
change  and  decay,  nay,  even  death  itself,  is  clearly 
foreshadowed  in  the  properties  of  nitrogen.  When 
the  Creator  first  endowed  this  element  with  its 
feeble  affinities,  He  also  passed  the  doom  of  all  liv- 
ing creatures  :  "  Dust  thou  art,  and  unto  dust  shalt 
thou  return." 

Here  I  must  leave  this  division  of  my  subject. 
It  would  be  highly  interesting  to  study  the  innu- 
merable phases  in  which  nitrogen  manifests  itself 
in  the  world  of  living  matter  ;  to  trace  how,  under 
the  guidance  of  that  mysterious  principle  of  life,  the 
most  complex  organic  compounds  are  educed  from 
such  simple  materials  as  water,  carbonic  acid,  am- 
monia, and  nitric  acid ;  to  follow  these  nitrogenized 
compounds  through  their  varied  history,  from  the 
time  they  are  first  generated  in  the  plant  until  they 
are  incorporated  into  the  brain,  the  muscles,  and  the 
bones  of  man ;  to  notice  at  every  stage  the  same 
instability  which  so  strikingly  characterizes  all  the 
compounds  of  this  singular  element,  capable  of  exist- 
ing only  under  the  continued  influence  of  the  vital 
principle,  and,  when  that  ceases  to  act,  gradually 
degenerating  and  falling  back  into  the  simple  pro- 
ducts from  which  they  sprang ;  but  all  such  details 
would  be  incompatible  with  the  plan  of  these  Lec- 
tures, and  must  therefore  be  reluctantly  passed  by. 


LECT.  VII.]  TESTIMONY   OF   NITROGEN. 

If,  however,  I  have  been  able  to  place  before  you  in  a 
clear  light  the  main  features  of  this  remarkable  ele- 
ment, —  its  isolated  existence  in  the  atmosphere,  its 
unparalleled  inertness  in  the  aeriform  condition,  its 
power  of  combination  under  restricted  conditions, 
the  great  variety  and  complexity  of  its  compounds, 
and,  finally,  their  singular  proneness  to  decomposi- 
tion and  decay,  —  it  is  all  that  I  could  expect.  We 
have  seen  that  in  each  of  these  respects  nitrogen 
has  been  adapted  with  exquisite  skill  to  the  unique 
part  which  it  plays  in  the  scheme  of  the  world ;  and 
this  element,  although  outwardly  so  unattractive 
and  dull,  has  borne  the  richest  testimony  to  the 
wisdom,  the  goodness,  and  the  power  of  God. 

Having  now  become  acquainted  with  the  charac- 
teristic features  of  nitrogen,  let  us  next  consider 
the  part  which  this  element  plays  in  that  circulation 
grand  circulation  of  matter  in  organic  na-  ofnitr°sen- 
ture,  which  has  been  already  in  part  described.  I 
have  before  stated  that  the  plant  is  a  true  apparatus 
of  reduction,  in  whose  leaves  carbonic  acid  is  decom- 
posed by  the  solar  light.  The  plant  absorbs  car- 
bonic acid  partly  through  its  leaves  from  the  air, 
and  partly  through  its  roots  from  the  soil.  The 
sun's  rays,  acting  upon  the  green  surface  of  the  leaf, 
decompose  in  some  mysterious  way  the  carbonic 
acid,  overcoming  the  intense  affinities  of  its  ele- 
ments, fixing  the  carbon,  and  setting  free  the  oxy- 
gen, to  be  restored  to  the  air.  From  the  carbon 
thus  obtained,  and  from  the  water,  ammonia,  and 


230  RELIGION   AND    CHEMISTRY.  [LECT.  VII. 

nitric  acid,  which  are  the  other  articles  of  its  food, 
together  with  a  few  inorganic  salts,  the  plant  con- 
structs its  tissues.  If  in  their  production  carbonic 
acid  and  water  alone  take  part,  there  result  such 
The  plant  substances  as  woody  fibre,  starch,  gum, 

ofPor°gda^cr  and  sugar?  and  of  tnese  nine  tenths  of  all 
materials.  vegetable  structures  consist.  If  the  ni- 
trogen compounds  are  likewise  employed  in  the 
process,  there  are  formed,  besides,  such  nitrogen- 
ized  products  as  albumen,  casein e,  and  fibrine. 
These  last  names  may  not  be  so  familiar  to  you  as 
the  first,  but  you  are  equally  familiar  with  the  sub- 
stances, and  will  recognize  them  at  once  when  told 
that  the  white  of  an  egg  is  nearly  pure  albumen, 
that  cheese  consists  almost  entirely  of  caseine,  and 
meat  of  fibrine.  Although  these  substances  are 
best  known  to  us  as  animal  products,  they  are  like- 
wise found  in  all  those  vegetables  which  are  articles 
of  food.  Albumen  and  caseine  can  readily  be  ex- 
tracted from  either  peas  or  potatoes,  and  gluten, 
the  substance  which  gives  tenacity  to  flour-paste, 
has  the  same  composition  as  animal  fibrine. 

The  animal,  unlike  the  plant,  has  not  the  power 
of  forming  the  substance  of  its  tissues  from  inor- 
ganic  compounds,  but  it  receives  them 

The  animal 

an  assimiiator  ready  formed  from  the  vegetable  king- 
ner>  dom.  It  transmutes  the  vegetable  prod- 
ucts into  a  thousand  shapes  in  order  to  adapt  them 
to  its  uses,  but  its  peculiar  province  is  to  assimilate 
and  consume,  not  to  produce.  The  nitrogenized 
compounds  just  referred  to  are  the  portion  of  its 


LECT.  VH.]  TESTIMONY   OF   NITKOGEN.  231 

food  which  supplies  the  constant  waste  attending  all 
the  vital  processes.  The  non-nitrogenized  starch 
and  sugar,  although  they  form  the  greater  part  of 
our  food,  are  never  actually  incorporated  into  the 
tissues  of  the  body,  and,  as  we  have  already  seen,  are 
merely  the  fuel  by  which  its  temperature  is  main- 
tained. The  animal  may  either  receive  its  nitro- 
genized  food  directly  from  the  plant,  as  is  the  case 
with  all  herbivora,  or  only  indirectly,  like  the  carniv- 
ora ;  but  in  either  case  the  origin  is  the  same,  and 
by  the  process  of  digestion  these,  originally  at  least, 
vegetable  products  are  assimilated  and  converted 
into  bones,  muscles,  or  nerves,  as  the  necessities  of 
the  animal  may  require.  We  find  that  during  this 
process  these  substances  do  not  undergo  any  funda- 
mental change,  but  merely  become  parts  of  more 
finely  organized  tissues.  We  discover  in  the  blood 
albumen  and  caseine,  having  precisely  the  same 
composition  as  that  which  may  be  prepared  from 
potatoes,  and  the  substance  of  the  muscle  does  not 
diifer  essentially  from  the  gluten  of  flour-meal. 

Do  not,  however,  suppose  that  the  part  of  the  ani- 
mal is  less  noble  than  that  of  the  plant.  It  is  really 
much  hio-her.  We  must  be  careful  to  make 

Distinction  be- 

a  distinction,  too  frequently  overlooked,  tween  matter 
between  the  organized  structure  and  the 
material  of  which  it  consists.     There  is  the  same 
difference  here  as  between  a  house  and  the  bricks 
of  which  it  is  built.     It  was  formerly  supposed  that 
organic  matter  was  formed  under  peculiar  influences, 
and  subject  to  special  laws.     But  it  is  now  known 


232  RELIGION   AND    CHEMISTRY.  [LECT.  VH. 

that  animal  and  vegetable  substances  obey  the  same 
laws  of  affinity  as  mineral  matter,  and  the  recent 
progress  of  chemistry  has  given  us  great  reason  to 
believe  that  we  may  be  able  one  day  to  prepare  all 
the  materials  of  which  plants  and  animals  build 
their  cells.  Here,  however,  chemistry  stops  and  cre- 
ation begins.  The  great  Architect  of  nature  alone 
can  fashion  this  dead  material  into  living  forms.* 
The  vegetable  kingdom  is  a  great  laboratory,  in 
which  the  sun's  rays  manufacture  from  the  gases 
of  the  atmosphere,  and  from  a  few  earthy  salts  of 
the  soil,  the  different  materials  which  the  organic 
builders  employ.  There  the  bricks  are  made,  and 
from  these  the  animal  builds  his  bones  and  muscles. 
He  does  not  make  the  bricks,  but  he  does  what  is 
far  more  glorious,  he  builds  with  them  his  delicate 
frame,  and  as  the  work  of  the  builder  is  higher 
than  that  of  the  brick-maker,  so  in  the  scale  of  be- 
ing is  the  animal  higher  than  the  plant,  and  the 
,more  noble  in  proportion  as  its  structure  is  more 
intricate  and  elaborate. 

While  the  plant  is  a  true  apparatus  of  reduction, 
the  animal  is  a  true  apparatus  of  combustion,  in 
which  the  substances  it  derived  from  the  vegetable 
are  burnt  and  restored  to  the  atmosphere  in  the 
form  of  carbonic  acid,  water,  and  ammonia,  ready  to 

*  I  do  not  forget  the  alleged  facts  of  spontaneous  generation ;  but  in 
all  cases  where  living  organisms  have  been  produced  without  visible 
germs,  there  has  been  a  falling  back  of  organized  material  from  a  higher 
to  a  lower  condition ;  and,  if  we  except  certain  very  untrustworthy  ex- 
periments of  the  late  Mr.  Weekes,  in  no  case  has  even  the  lowest  type 
of  an  organic  cell  been  produced  from  unorganized  matter,  unless 
through  the  natural  processes  of  growth. 


LECT.VH.]  TESTIMONY   OF  NITROGEN.  233 

be  again  absorbed  by  the  plant  and  to  repass  through 
the  phases  of  organic  life.  Our  bodies  are  furnaces, 
—  furnaces  continually  burning.  —  whose 

•*  *  Motion  in  the 

fuel  is  our  own  flesh,  and  the  smoke  of  ammai  the  re- 
whose  fires  is  the  food  of  the  plant. 
Every  time  I  strike  a  blow  a  portion  of  the  mus- 
cle is  consumed,  actually  burnt  up  in  producing 
the  force.  In  every  muscular  effort  I  make,  in 
every  word  I  utter,  in  every  step  I  take,  a  por- 
tion of  the  muscles  concerned  is  burnt,  and  motion 
can  no  more  be  produced  in  the  animal  body  with- 
out a  combustion  of  its  tissues,  than  it  can  be  gen- 
erated in  a  steam-engine  without  burning  fuel  un- 
der its  boiler.  As  in  the  steam-engine  the  burning 
fuel  is  the  source  of  its  power,  so  in  the  animal 
body  the  burning  muscle  is  the  immediate  cause 
of  all  its  motions.  I  will  to  strike  a  blow,  but  it  is 
not  I  that  produce  the  motion.  It  is  the  muscle, 
and  in  the  exertion  the  muscle  is  consumed.  The 
muscle,  however,  does  not  originate  the  motion, 
any  more  than  the  fuel  originates  the  motion  of 
the  steam-engine.  The  fuel,  we  have  seen,  does 
not  originate  heat.  It  is  merely  a  reservoir  of 
heat,  and  in  burning  it  merely  gives  up  the  heat 
it  once  received  from  the  sun.  So  the  muscle  is 
merely  a  reservoir  of  force,  and  in  burning  it  gives 
out  the  force  it  contains.  The  force  it  contains  it 
also  received  from  the  sun,  when  its  substance  was 
formed  by  the  sun's  rays  acting  upon  the  leaves  of 
the  plants. 

What  a  wonderful  revelation  is  this !     Muscular 


234  RELIGION   AND    CHEMISTRY  [LECT.  Vn. 

power  originates  in  the  sun.  We  do  not  create 
Muscular  the  force ;  we  do  not  originate  it ;  we 
nr/inte  merely  excite  it.  The  force  which  origi- 
6un-  nally  came  from  the  sun  lies  dormant  in 

the  muscles  until  our  will  calls  it  into  activity. 
Our  bodies  are  machines,  perfect  machines  it  is 
true,  but  yet  machines.  Like  all  other  machines, 
they  merely  transmit  power,  they  cannot  create  it. 
They  very  closely  resemble  a  steam-engine.  As  we 
must  constantly  feed  the  engine  with  fuel,  so  we 
must  supply  our  bodies  with  food  in  order  to  repair 
the  muscle  which  is  burnt,  and  we  can  no  more  be 
said  to  originate  that  force  which  manifests  itself  in 
our  bodies,  than  the  stoker,  who  shovels  the  fuel 
into  the  grate,  can  be  said  to  originate  the  force  of 
the  steam-engine.  We  are  not  our  bodies,  although 
we  live  in  them,  and  direct  their  motions.  They 
move  by  forces  which  emanate  from  a  source  far 
higher  than  us,  and  we  stand  in  the  same  relation 
to  them  in  which  an  engineer  does  to  his  machine. 
Certainly  Lavoisier,  the  great  father  of  modern 
chemistry,  had  caught  a  glimpse  of  the  results 
which  it  has  been  left  for  more  modern  science  to 
establish,  when  he  wrote  :  "  Organization,  sensation, 
voluntary  motion,  life,  only  exist  on  the  surface  of 
the  earth,  and  in  places  exposed  to  the  light.  It 
might  be  said,  indeed,  that  the  fable  of  Prometheus 
was  an  expression  of  a  philosophical  truth,  which 
had  not  escaped  the  penetration  of  the  ancients. 
Without  light,  nature  were  without  life  and  with- 
out soul ;  a  beneficent  God,  in  shedding  light  over 


TESTIMONY   OF  NITROGEN.  235 

creation,  strewed  the  surface  of  the  earth  with  or- 
ganization, with  sensation,  and  with  thought." 

Although,  my  friends,  it  thus  appears  that  our 
bodies  are  mere  channels  of  force,  machines  whose 
motive  power  emanates  from  the  great 

0      m         Relation  of 

centre  of  the  solar  system,  let  us,  while  mind  to 
we  recognize  this  startling  result  of  sci- 
ence, remember  the  no  less  certain  fact  of  conscious- 
ness, —  that  we  are  not  our  bodies,  though  we  live 
in  them,  —  that  this  conscious  personality  is  some- 
thing entirely  apart  from,  and  infinitely  superior  to, 
these  corporeal  atoms  in  which  it  is  temporarily  en- 
shrined, surviving  as  it  does  all  their  changes.  Let 
us  also  keep  clearly  in  view  the  still  more  glorious 
truth,  that  this  machine,  with  all  its  infinite  capabil- 
ities of  good  and  evil,  is  put  entirely  at  our  com- 
mand ;  that  not  one  conscious  motion  can  take 
place  unless  we  will  it ;  and  that  this  will  of  ours  can 
set  in  action  a  chain  of  causes  which  no  space  can 
bound  and  no  time  can  limit.  Let  us  then  well  con- 
sider how  great  is  the  power  which  has  thus  been 
delegated  to  us,  let  us  duly  weigh  the  awful  respon- 
sibility it  involves,  and  so  act  that,  when  the  Master 
claims  his  own,  we  may  not  be  ashamed  to  render 
up  the  account  of  our  stewardship. 

Moreover,  although  it  is  true  that  these  bodies 
themselves  are  constantly  dissolving  into  air,  that 
the  material  atoms  which  compose  them  will  in  a 
few   short  weeks   all  be  gone,  and  that  Thevitai 
there  is  nothing  but  the  shadow  of  our  PrinciPle' 
forms  which  we  can  call  our  own,  we  must  also  re- 


236  RELIQION   AND    CHEMISTRY.  [LECT.  VH. 

member  that  there  is  a  mysterious  principle  with- 
in, constantly  renewing  and  reparing  our  wasting 
frames, — a  cunning  architect  superintending  a  thou- 
sand builders  who  are  constantly  reconstructing, 
with  materials  prepared  by  vegetation,  the  bones, 
the  muscles,  and  the  nerves,  as  fast  as  they  are 
wasted  and  consumed ;  making,  in  a  most  mysteri- 
ous way,  beyond  all  human  comprehension,  here  the 
fibre  of  a  muscle,  there  the  filament  of  a  nerve,  here 
building  up  a  bone,  there  uniting  a  tendon,  fashion- 
ing each  with  scrupulous  nicety,  and  fitting  each  to 
its  place  with  never-failing  skill.  But  no  sooner  is 
the  work  of  the  architect  done,  than  another  great 
power  comes  in  to  destroy  it.  The  oxygen  gas 
which  the  blood  absorbs  in  the  lungs  and  carries 
to  the  different  parts  of  the  body  burns  up  these 
carefully  elaborated  tissues,  converting  them  into 
carbonic  acid,  water,  and  ammonia,  which  pass 
into  the  atmosphere,  from  which  they  originally 
came.  Life  is,  in  fact,  a  constant  struggle  be- 
tween the  builders  and  the  destroying  element  of 
the  air ;  and  when  its  short  term  is  ended,  and  the 
builders  cease  because  they  are  wearied  and  few, 
then  u  the  dust  returns  to  the  earth  as  it  was,  and 
"  the  spirit  returns  unto  God  who  gave  it." 

But  let  us  not  sorrow  as  those  who  have  no  hope ; 
"  for  we  know  that  if  our  earthly  house  of  this  tab- 
"  ernacle  was  dissolved,  we  have  a  building  of  God, 
"  an  house  not  made  with  hands,  eternal  in  the 
"heavens."  And  cannot  He  who  has  clothed  us 
with  our  earthly  house  provide  for  us  a  better  and 


TESTIMONY   OF  NITROGEN.  237 

more  enduring  mansion  ?  and  are  not  all  these  won- 
derful changes  in  our  present  bodies  a  foreshadow- 
ing of  the  final  consummation,  when  our  earnest  de- 
sire "  to  be  clothed  upon "  shall  be  satisfied,  and 
"  mortality  shall  be  swallowed  up  of  life  "  ? 

Such  is  a  very  imperfect  sketch  of  that  great 
cycle  of  changes,  of  which  all  organic  nature  is 
merely  a  passing  phase.  Let  us  review 
for  a  moment  its  main  features.  When 
the  foundations  of  the  globe  were  laid,  there  were 
collected  in  the  atmosphere  all  the  essential  ele- 
ments of  organized  beings.  From  this  inexhaust- 
ible storehouse  the  plant  absorbs  water,  carbonic 
acid,  and  ammonia,  which  were  placed  there  for  its 
use,  and  which  have  been  made  to  serve  as  its  nour- 
ishment and  food.  It  is  the  special  office  of  the 
plants  to  elaborate  from  these  few  mineral  sub- 
stances, and  a  small  amount  of  earthy  salts,  all  the 
materials  of  organized  beings.  The  animal  receives 
these  crude  materials  already  prepared,  and  builds 
with  them  its  various  tissues ;  but  no  sooner  are 
the  cell-walls  finished,  and  the  structure  ready  to 
discharge  its  vital  functions,  than  it  is  consumed 
by  almost  the  very  act  which  gave  it  life.  The  car- 
bonic acid,  water,  and  ammonia  are  restored  to  the 
atmosphere,  and  the  cycle  is  complete. 

Of  this  Divine  economy  the  sun's  rays  are  the 
great  moving  cause,  and  it  is  their  mysterious  power 
which  is  constantly  reappearing  in  all  the  varied 
phases  of  organic  life.  And  not  in  these  alone; 
for,  as  we  have  seen,  this  same  gentle  influence 


238  RELIGION   AND    CHEMISTRY.  [LECT.  VII. 

keeps  in  motion  the  aerial  currents  which  blow  our 
ships  across  the  ocean.  It  raises  the  water  which 
turns  the  wheels  of  our  factories.  It  drives  the  lo- 
comotive over  the  iron  road,  and  impels  the  steamer 
through  the  waves.  It  roars  at  the  cannon's  mouth, 
and  charges  the  grander  artillery  of  the  skies. 
There  is  no  motion  on  the  globe  which  cannot  be 
traced  directly  or  indirectly  to  the  sun,  and  were 
his  rays  to  lose  their  mysterious  power,  all  nature 
would  become  silent,  motionless,  and  dead.* 

But  in  thus  tracing  to  the  sun  all  these  varied 
phenomena,  let  us  not  forget  that  we  have  not  yet 
found  the  great  First  Cause.  The  problem  is  not  yet 
solved ;  the  profoundest  truth  has  yet  to  be  told. 
This  mysterious  force,- which  the  sun  pours  in  cease- 
less floods  upon  the  earth, — whence  comes  it?  You 
have  already  answered  the  question.  The  answer 
is  on  your  lips.  I  have  but  to  re-echo  it,  and  how 
can  I  better  do  this  than  in  the  words  of  that  blind 
poet  to  whom  misfortune  had  revealed  the  true 
meaning  of  light! 

"  Hail,  holy  Light !  offspring  of  Heaven  first  born ; 
Or  of  the  Eternal  co-eternal  beam 
May  I  express  thee  unblamed  ?  since  God  is  light, 
And  never  but  in  unapproached  light 
Dwelt  from  eternity,  dwelt  then  in  thee, 
Bright  effluence  of  bright  essence  increate." 

*  For  a  most  eloquent  statement  of  the  same  truth  I  would  refer  the 
reader  to  the  closing  chapter  of  a  recent  work  by  Professor  Tyndall  of 
London,  on  Heat  considered  as  a  Mode  of  Motion.  It  is  but  justice  to 
myself  to  state  that  the  last  half  of  the  present  Lecture  was  first  deliv- 
ered before  the  Lowell  Institute,  in  Boston,  in  the  winter  of  1853-54, 
essentially  as  it  now  stands. 


LECTURE    VIII. 

ARGUMENT  FROM   SPECIAL  ADAPTATIONS. 

I  HAVE  endeavored  thus  far  in  this  course  of  Lec- 
tures to  present  a  few  of  the  prominent  illustrations 
of  the  attributes  of  God,  which  have  been  discovered 
in  the  adaptations  of  the  atmosphere  to  the  condi- 
tions of  organic  life  on  the  earth.  We  have  read  to- 
gether one  brief  chapter  of  that  evidence  of  design 
with  which  the  book  of  nature  is  filled,  and 
I  cannot  but  trust  that  we  have  gained  a  proof  of 
from  our  study  nobler  conceptions  and  G 
more  enlarged  views  of  the  wisdom,  power,  and 
goodness  of  our  Heavenly  Father.  Every  one  who 
accepts  the  Bible  as  a  divine  revelation  will  rejoice 
to  find  how  beautifully  and  how  entirely  the  facts  of 
science  confirm  its  great  fundamental  truths.  But 
have  not  these  evidences  of  nature  a  greater  value 
even  than  this?  Do  they  not  prove,  independently 
of  all  revelation,  the  existence  of  a  wise  and  omnipo- 
tent First  Cause,  at  least  so  far  as  there  is  any  moral 
certainty  in  the  world  ?  I  am  persuaded  that  they 
do,  and  I  believe  that  they  furnish  the  only  logical 
ground  on  which  a  system  of  revealed  religion  can 
be  based.  In  my  introductory  Lecture  I  stated 
that  I  preferred  to  discuss  the  adaptations  of  nature 
as  illustrations  of  the  attributes  of  God,  rather  than 

16 


240  RELIGION   AND    CHEMISTRY.  [LECT.  VIII. 

as  absolute  proofs  of  His  being ;  but  now  that  we 
have  surveyed  the  ground,  let  us  consider  whether 
they  are  not  really  moral  proofs,  with  all  the  cer- 
tainty that  any  proof  not  strictly  a  mathematical 
demonstration  can  give. 

The  argument  from  adaptation  is  one  which  ad- 
dresses itself  to  every  human  being.  It  is  suited  to 
every  intellect,  and  comes  home  to  every  man's  ex- 
characterof  perience.  It  is  based  on  a  principle  of 
the  argument.  fae  human  mind,  —  whether  the  result  of 
experience  or  of  intuition  we  need  not  inquire, — 
which  compels  it  to  infer  design  when  it  sees  adap- 
tation. Who  doubts  that  the  flint  arrow-heads  and 
stone  implements  found  in  New  England,  rough  and 
misshapen  as  they  are,  were  made  by  men  ?  To 
question  the  universal  belief  would  be  regarded  as 
little  short  of  insanity.  Why  then  not  apply  the 
same  common  sense  to  the  interpretation  of  na- 
ture ?  The  unlettered  do,  and  believe,  in  their  simple 
faith,  that  the  feathered  songster  and  the  delicate 
flower  were  made  by  their  Heavenly  Father's  hand. 
It  is  only  those  of  us  whose  minds  have  been  un- 
settled by  the  subtilties  of  logic  who  doubt,  and,  if 
we  could  analyze  our  doubts,  I  think  they  would  be 
found,  in  most  cases,  to  arise  from  a  vague  fear  that, 
since  nature  stands  on  a  level  so  much  above  man's 
experience,  the  ordinary  principles  of  reasoning  may 
possibly  not  apply,  and  we  may  be  misled  by  appar- 
ent analogies.  But  why  this  fear  ?  There  is  no 
essential  difference  between  the  adaptations  found 
in  nature  and  the  adaptations  made  by  men.  Both 


LECT.  VHL]    ARGUMENT   FROM   SPECIAL   ADAPTATIONS.        241 

employ  means  to  attain  some  important  result,  and 
in  many  cases  they  secure  the  end  by  precisely  the 
same  means.  The  telescope  and  microscope  are  but 
reproductions  of  the  eye,  and,  although  very  imper- 
fect reproductions  at  the  best,  they  imitate  in  all 
their  essential  features  this  beautiful  optical  appara- 
tus of  nature.*  It  is  true  that  the  adaptations  of  na- 
ture are  vastly  superior  to  the  results  of  human  skill, 
and  it  is  also  true  that  their  origin  is  beyond  our 
personal  experience.  We  have  seen  the  process  of 
making  a  watch  and  the  process  of  making  a  tele- 
scope. "We  know  how  the  principles  of  both  were 
discovered,  and  the  whole  subject  lies  within  the 
range  of  our  experience ;  but  no  man  ever  made  or 
ever  can  make  an  eye,  and  the  whole  process  of  its 
growth  and  development  is  utterly  beyond  the 
range  even  of  man's  conception.  All  this  is  true  ; 
but  if  you  reflect  a  moment,  you  will  find  that  this  is 
just  what  is  to  be  expected,  seeing  that  God  is  the 
Creator  and  we  are  His  creatures,  and  so  far  from 
weakening,  this  very  characteristic  greatly  strength- 
ens the  evidence.  Moreover,  it  must  be  remem- 

*  The  power  which  the  eye  possesses  of  adaptation  to  near  and  dis- 
tant objects,  combining  the  uses  of  the  microscope  and  the  telescope, 
and  the  capacity  of  self-adjustment,  preserving  always  a  perfect  achro- 
matism and  freedom  from  spherical  aberration,  have  never  been  reached 
in  nearly  the  same  degree  by  art.  Moreover,  in  the  eye  this  perfection 
is  attained  with  a  focal  length  of  only  half  an  inch,  which  vastly  in- 
creases the  difficulty.  It  is  also  a  fact  worthy  of  notice,  that  the  improve- 
ments in  optical  instruments  have  preceded  rather  than  followed  the 
discoveries  of  physiologists,  thus  serving  to  explain  the  functions  of 
the  eye ;  and  inventions  like  that  of  achromatic  lenses,  to  which  men 
have  been  led  by  theoretical  study,  have  been  found  to  be  anticipated 
in  nature. 


242  RELIGION   AND    CHEMISTRY.  [LECT.  VIII. 

bered  that,  if  the  design  is  of  an  infinitely  higher 
order,  the  evidence  of  the  design  is  infinitely  more 
ample.  A  rude,  misshapen  image  is  a  convincing 
evidence  of  human  intelligence ;  but  all  nature  with 
its  numberless  adaptations  —  from  the  properties  of 
the  crude  elements  up  to  the  wonderful  structure 
of  the  human  frame  —  is  given  us  as  evidence  of 
the  wisdom  of  God. 

The  argument  from  the  adaptations  of  nature  is 
of  the  kind  we  call  cumulative.  Its  force  depends 
on  the  concurrence  of  many  and  varied  The  argument 
examples.  It  is  not  based  on  one  isolated  cumulative- 
case  of  adaptation,  or  even  on  a  thousand ;  but 
there  is  a  host  of  conditions,  which  no  man  can 
number,  each  adjusted  to  each,  and  all  bound  to- 
gether in  one  harmonious  whole.  Consider  only 
the  examples  we  have  discovered  in  the  very  nar- 
row field  to  which  we  have  limited  our  study. 
How  numberless  are  the  conditions  on  which  the 
harmonious  working  of  the  varied  functions  of  the 
atmosphere  depends !  In  the  first  place,  there  is 
the  expansive  tendency  of  the  air,  sustained  by  the 
solar  heat,  and  restrained  by  the  force  of  gravity, 
by  which  alone  it  is  held  to  the  surface  of  the 
globe.  Then  there  is  the  density,  exactly  adjusted 
to  the  human  organism,  and  depending  on  the 
measures  and  weights  of  the  solar  system.  Next 
there  are  all  the  delicate  relations  to  light,  heat, 
and  electricity.  Passing  to  the  separate  constitu- 
ents of  the  atmosphere,  there  is  oxygen,  with  its 
three  distinct  modifications,  endowed  with  fiery 


LECT.VHI.]    ARGUMENT   FROM   SPECIAL  ADAPTATIONS.        243 

affinities,  and  yet  so  carefully  guarded  as  to  be  a 
beneficent  servant  of  man,  intrusted  with  most 
varied  and  seemingly  incompatible  functions,  and 
discharging  each  with  equal  fidelity  and  precision ; 
next,  there  is  water,  nourishing  all  nature  with  its 
dews  and  rains,  tempering  the  polar  climates  with 
the  latent  warmth  of  its  genial  currents,  and  pro- 
tecting with  its  great  frost-blanket  the  delicate 
plants  from  the  winter's  cold,  —  exceptional  in  all 
its  qualities,  and  each  adapted  to  some  beneficent 
end;  then  comes  carbonic  acid,  concealing  in  its 
transparent  folds  the  solid  frame-work  of  all  organ- 
ized beings,  and  the  source  of  those  priceless  beds 
of  coal,  with  their  inexhaustible  stores  of  heat  and 
force  ;  and  lastly,  but  not  least  in  interest  or  impor- 
tance, there  is  nitrogen,  so  remarkably  inert,  and 
yet  endowed  with  such  varied  affinities,  forming 
such  numberless  compounds,  and  imparting  to  all 
such  singular  instability.  As  we  thus  hastily  re- 
view the  ground  we  have  surveyed  together,  you 
will  recall  the  numerous  adaptations  which  we  dis- 
covered while  studying  the  wonderful  cycles  of 
change  in  which  all  these  substances  conspire,  wheel 
revolving  within  wheel,  and  yet  all  moving  with 
such  delicacy  and  beauty  of  adjustment  that  no  jar 
is  felt  through  all  this  complicated  mechanism,  and 
not  the  slightest  derangement  occurs  in  any  of  its 
ten  thousand  parts. 

Now  the  argument  for  design  unfolded  in  this 
brief  chapter  of  the  book  of  nature  comes  home  to 
us  with  the  cumulative  weight  of  all  this  testimony, 


244  RELIGION  AND    CHEMISTRY.  [LECT.  VIII. 

Perhaps  plausible  objections  might  be  urged  against 
individual  examples  of  adaptation  which  have  been 
advanced ;  but  any  one  who  questions  the  general 
fact  must  be  prepared  to  disprove  all.  Were  there 
but  a  single  instance  of  adaptation,  or  only  two  or 
three,  the  sceptic  might  urge  with  a  show  of  rea- 
son that  this  was  the  result  of  accident,  —  arose 
from  the  "  fortuitous  concourse  of  atoms  " ;  but  the 
examples  of  adaptations  which  we  have  discovered 
merely  in  the  atmosphere,  all  interlacing  with  each 
other,  and  all  working  together  in  the  general 
scheme,  are  by  themselves  alone  so  great  a  number 
that,  if  we  take  no  higher  ground  than  the  mathe- 
matical theory  of  probabilities,  the  chances  against 
the  supposition  that  this  system,  even  as  we  know 
it,  was  the  result  of  accident,  are  almost  infinite, 
and  can  be  expressed  numerically  only  when  the 
sands  on  the  sea-shore  are  counted.  If  such,  then, 
is  the  weight  of  the  evidence  which  the  atmosphere 
gives,  what  must  be  the  force  of  the  argument  in 
which  all  nature  gives  its  united  testimony  ?  Truly, 
the  number  of  atoms  in  the  universe  is  not  suffi- 
ciently large  to  express  the  probabilities  against 
this  forlorn  hope  of  atheism! 

But,  my  friends,  the  sceptic  should  be  heard,  and, 
having  presented  our  side,  let  us  listen  to  what  he 
summingupof  has  to  say  in  reply.  The  whole  argu- 
the  argument.  ment  from  special  adaptations  may  be 
summed  up  in  a  few  words.  Within  the  sphere  of 
human  experience,  adaptation  proves  the  existence 
of  an  intelligence  adequate  to  the  conception  and 


LECT.  VIIL]     ARGUMENT  FROM   SPECIAL  ADAPTATIONS.        245 

execution  of  the  design.  "We  find  in  nature  adapta- 
tions similar  to  the  results  of  human  intelligence, 
only  of  an  infinitely  higher  order,  and  hence  by 
analogy  we  conclude  that  these  must  have  issued 
from  an  infinitely  wise  and  omnipotent  Designer. 
The  argument  assumes  the  reality  of  the  human  in- 
telligence as  consciously  a  power  and  an  originator 
within  its  own  sphere,  and  reasons  from  this  to  a 
similar  conscious  intelligence  in  the  Author  of  na- 
ture. The  argument  assumes,  also,  the  truthfulness 
of  the  human  faculties  as  a  source  of  knowledge, 
without  which  it  is  of  course  useless  to  reason 
at  all. 

Now  the  adaptations  of  nature  are  facts  which 
every  one  must  admit,  the  sceptic  among  the  rest. 
Moreover,  he  must  also  admit  that  the 

Burden  of 

conclusion  which  we  have  drawn  from  proof  is  with 
these  premises  is  the  all  but  universal 
conclusion  of  mankind.  Plutarch,  writing  eighteen 
centuries  ago,  without  the  light  of  the  Christian 
revelation,  bears  this  remarkable  testimony  to  the 
universality  of  the  religious  idea  :  "  If  you  go 
through  the  world,  you  may  find  cities  without 
walls,  without  letters,  without  rulers,  without  dwell- 
ings, without  wealth,  without  money,  without  thea- 
tres and  manly  sports ;  but  there  was  never  yet 
seen  nor  shall  be  seen  by  man  a  single  city  without 
temples  and  gods,  or  without  prayers,  oaths,  proph- 
ecies, and  sacrifices,  used  to  obtain  blessings  and 
benefits,  or  to  avert  curses  and  calamities.  Nay,  I 
am  of  opinion  that  a  city  might  be  sooner  built 


246  RELIGION   AND    CHEMISTRY.  [LECT.  VIII. 

without  any  ground  beneath  it,  than  a  common- 
wealth could  be  constituted  altogether  destitute  of 
belief  in  the  gods,  or,  being  constituted,  could  be 
preserved."  *  The  discoveries  of  modern  travellers 
have  not  more  fully  confirmed  the  general  truth  of 
Plutarch's  statement,  than  the  experiments  of  mod- 
ern socialists  have  proved  the  soundness  of  his 
opinion.  No  savage  tribe  has  yet  been  found  on 
which  a  belief  in  a  higher  power  has  not  at  least 
glimmered,  and  no  community  which  has  attempted 
to  ignore  religion  has  lasted  a  generation.  The 
sceptic,  then,  if  he  rejects  our  conclusion,  is  bound 
to  prove  that  the  natural  inference  of  man  is  based 
in  error.  If  he  sets  aside  the  general  rule  of  faith, 
and  refuses  assent  to  the  universal  creed,:  —  "Quod 
semper,  quod  ubique,  quod  ab  omnibus  creditum 
est,"  •)•  —  he  must  explain,  whatever  theory  he  may 
adopt,  how  it  comes  to  pass  that  all  mankind  have 
been  duped,  and  all  nature  has  issued  in  a  lie.  The 
burden  of  proof  is  with  him,  and  how  does  he  meet 
it  ?  Generally,  in  one  of  two  ways. 

In  the  first  place,  he  attacks  the  validity  of  the 
conclusion  on  purely  speculative  grounds,  saying 
universal  that  adaptation  is  no  longer  an  evidence 
scepticism.  of  (jesign  when  applied  to  subjects  beyond 


*  Evpoi?  8'  av  e-rriuv  ir6\€LS  aret^iorovy,  aypa/ifiarovy,  a/3ao-iXevrous, 
aotKovs,  dxprjpdrovsj  vo/iur/Aaros  pr)  Seo/zeras,  dncipovs  Qedrpcov  KOI  yvpva- 
(ria>v  dviepov  8e  TtxJXecos  Kal  dOeov.  pr)  xpco/ieir/s  ei^ais,  /«7§e  opKots,  prjbe 
fj.avTfia.is,  p.T]8e  dvcriais  CTT*  dya6ois,  p-rjff  dTTOTpo-rrals  KCIK&V,  ovfteis  eamv 
ouS*  carat  ytyovws  Oear^s  •  aXXa  iro\is  av  pot  8o*et  paX\ov  edd<povs  X^piSi 
77  TroXtreia  rrjs  irepl  6fa>v  SO^TJS  ixpatpeOeioys  navraTraa-t,  <rvcrra<ri.v  Xa/3elv, 
rj  Xa/3oi)a-a  rrjp^a-ai.  Plutarch,  Hpbs  KdXarrjv,  xxxi. 

f  Vincentius  Lerinensis,  written  434  A.  D. 


LECT.  VIIL]    ARGUMENT  FROM   SPECIAL  ADAPTATIONS.        247 

the  range  of  all  human  experience.  He  may  sup- 
port this  position  by  questioning,  with  Hume,  the 
competency  of  the  human  faculties  as  a  source  of 
knowledge,  or,  like  Comte,  he  may  deny  all  final 
causes,  and  maintain  that  there  is  no  evidence  of 
anything  behind  the  external  phenomena  of  na- 
ture ;  but  whatever  form  the  scepticism  may  as- 
sume, the  conclusion  is  the  same,  and  the  argument 
for  design  is  ruled  out  as  invalid. 

With  regard  to  this  position  I  have  only  a  few 
words  to  say.  Design  in  nature,  I  admit,  cannot 
be  demonstrated :  for  the  truths  of  natural 

'  Design  not 

religion  cannot  be  evolved  from  a  math-  capable  of 
ematical  formula.  The  argument  is  based 
on  analogy,  and  although  the  analogies  are  so  close 
and  so  broad  that  to  my  mind  they  amount  to 
moral  proofs,  and  the  conclusion  appears  as  certain 
as  any  theorem  of  geometry,  still  I  admit  that,  in 
the  technical  language  of  logic,  the  evidence  is 
probable,  and  not  demonstrative.  But  as  a  student 
of  physical  science,  it  is  not  my  business  to  defend 
the  credibility  of  the  human  faculties,  or  to  discuss 
the  doctrine  of  causation.  The  task  belongs  to  the 
metaphysicians,  and,  as  I  stated  in  my  first  Lee- 
true,  I  shall  not  encroach  on  their  peculiar  province. 
Nor  do  I  think  it  important  to  dwell  on  the  value 
of  analogical  reasoning.  Modern  writers  have  not 
been  able  to  add  much  to  Bishop  Butler's  masterly 
discussion  of  the  subject,  and  every  man,  however 
sceptical  he  may  be  in  his  speculative  opinions, 
must  admit,  with  the  author  of  "  The  Analogy,"  that 


248  RELIGION   AND    CHEMISTRY.  [LECT.  VIII. 

"  probability  is  the  very  guide  of  life."  One  con- 
sideration, however,  may  be  of  value  in  answering 
objections ;  namely,  that,  since  the  difficulties  which 
are  found  in  natural  theology  reappear  with  equal 
strength  in  all  departments  of  knowledge,  no  objec- 
tions can  be  reasonably  urged  against  the  methods 
of  the  former,  which  apply  equally  well  to  our  most 
familiar  processes  of  thought.  It  may  be  fairly  pre- 
sumed that  such  objections  are  more  apparent  than 
real,  and  that  they  indicate  not  the  inconsequence 
of  our  logic,  but  only  the  necessary  limitations  of 
our  faculties. 

Now  analogy  is  not  only  the  guide  of  common 
life,  but  it  is  also  the  basis  on  which  physical 
science  chiefly  rests ;  and  if  this  method  of  reason- 
ing be  disallowed,  all  the  results  of  science  beyond 
those  of  mere  observation  and  demonstration  must 
fall  with  it.  It  is  frequently  said,  that  scientific 
truth  can  be  demonstrated,  but  religious  truth  must 
be  accepted  on  faith ;  and  in  part  this  is  true  ;  but 
the  statement  is  one  of  those  loose  sayings  whose 
province  of  partial  truth  only  renders  the  latent  error 
demonstration.  more  dangerous.  No  word  is  more  fre- 
quently misused  than  demonstration.  Technically, 
this  term  only  applies  to  that  form  of  absolute 
proof  with  which  we  deal  in  geometry  or  pure 
logic ;  but,  popularly,  a  principle  is  said  to  be  de- 
monstrated when  all  that  can  be  claimed  for  it  is  a 
high  degree  of  moral  certainty.  In  this  double  use 
of  the  term  the  error  of  the  above  statement  lies, 
for  it  is  made  in  one  sense,  and  —  frequently  at 


LECT.VIIL]    ARGUMENT  FROM   SPECIAL  ADAPTATIONS.        249 

least  —  understood  in  the  other.  Truth  wholly  new 
is  never  reached  by  demonstration ;  for  demonstra- 
tion cannot  yield  what  is  not  already  implied  in 
the  premises  with  which  it  starts.  The  truths  of 
geometry  and  mechanics  may  be  demonstrated ;  but 
then  they  are  virtually  contained  in  the  axioms  and 
definitions  on  which  these  sciences  rest.  All  scien- 
tific generalization  is  based  on  analogy ;  and  more- 
over, a  great  mass  of  the  scientific  truth  which  lies 
within  the  range  of  direct  observation  we  owe  to 
the  same  principle ;  for  even  here  analogy  directed 
the  student  to  what  he  subsequently  observed. 

Indeed,  the  great  inspiring  and  directing  power 
in  the  mind  of  the  successful  investigators  of  na- 
ture is  the  force  of  analogy.     It  is  this  Analogy  the 
which  constantly  leads  them  to  pronounce  ^^^1 
conclusions  unsound,  although  apparent-  science- 
ly  sustained  by  experiment,  and  to  accept  others 
which  are  seemingly  at  variance  with  facts.     It  is 
this  which  leads  them  through  long  and  laborious 
investigations  to  establish  principles  which  they  be- 
lieve to  be  true,  and  sustains  them  in  their  efforts 
through  successive  failures  to  ultimate  success.     As 
indefinite  and  uncertain  as  the  analogies  of  nature* 
frequently  seem   to   be,  as   unsatisfactory  as  they 
may  appear  to  the  great  mass  of  mankind,  and  as 
impossible  as  it  is  to  make  them  intelligible  except 
to  those  already  versed  in  scientific  inquiries,  yet 
the  history  of  science  shows  that,  when  based  on  an 
extended    knowledge    and   a   mature    experience, 
they  very  seldom  lead  astray. 


250  RELIGION   AND    CHEMISTRY.  [LECT.  VIII. 

The  method  of  scientific  discovery  is  frequently 
misunderstood,  and  the  philosophy  of  Bacon,  how- 
ever important  in  correcting  old  abuses, 
Bcientific°  has  done  not  a  little  towards  creating  the 
misapprehension.  Many  persons  seem  to 
think  that  the  author  of  the  Novum  Organum 
gave  to  man  a  rule,  by  which,  with  the  aid  of  a  sort 
of  mechanical  logic  called  induction,  the  laws  of  na- 
ture may  be  discovered,  very  much  as  a  last  is 
turned  out  by  a  lathe.  Yet  nothing  could  be  fur- 
ther from  the  truth.  So  far  as  the  observation  of 
phenomena  is  concerned,  —  which  must  always  be 
the  occupation  of  the  great  mass  of  scientific  men, 
—  the  methods  are  as  mechanical  as  those  of 
other  learned  professions,  requiring  chiefly  a  quick 
eye,  a  delicate  touch,  a  ready  perception,  and  most 
of  all  a  clear  head  capable  of  discriminating  between 
the  accidentals  and  the  essentials,  which  are  always 
singularly  blended  in  natural  phenomena.  But 
the  great  generalizations,  which  form  the  frame- 
work of  knowledge,  are  not  reached  by  rule ;  nor 
as  a  general  thing  are  they  in  their  inception  of 
slow  growth.  On  the  contrary,  they  usually  come 
'First  the  like  intuitions  to  the  mind,  with  the  ra- 
conception.  pj^ity  of  the  lightning's  flash,  and  it  is  fre- 
quently possible  to  mark  the  day  and  the  hour  when 
the  revelation  was  made.  But  such  revelations  of 
scientific  truth  are  vouchsafed  only  to  those  highly 
favored  minds  which  through  long  study  and  pa- 
tient investigation  have  been  brought  into  perfect 
sympathy  with  the  harmonies  of  nature ;  and  if  we 


LECT.  VIII.]     ARGUMENT   FROM   SPECIAL  ADAPTATIONS.        251 

analyze  the  conditions  of  the  mental  process,  we 
shall  find  that  these  great  discoveries  are  really  the 
result  of  analogical  reasoning. 

But  although  the  conception  is  thus  sudden,  the 
verification  of  the  truth  is  frequently  long  and  labo- 
rious. Great  discoveries  are  not  achieved  Afterwards  the 
in  an  hour  or  a  day.  Nature  has  so  con-  veriflcation- 
cealed  her  truths,  and  surrounded  them  by  so  many 
adventitious  circumstances,  that  they  can  be  dis- 
closed to  the  world  only  after  long  and  careful  study. 
First  comes  the  conception,  afterwards  the  toilsome 
investigation  by  which  it  is  proved  that  the  facts  of 
nature  accord  with  the  generalization.  The  inves- 
tigation may  lead  to  a  great  modification  of  the 
original  idea,  or  may  show  that  it  must  be  wholly 
abandoned,  and  meanwhile  another  may  have  ta- 
ken its  place,  to  go  through  the  same  scrutiny  in  its 
turn  ;  but  still  the  conception  which  proves  to  be 
the  law  of  nature  is  the  real  discovery.  This,  as 
we  have  seen,  is  the  result  of  analogy,  and  most 
clearly  vindicates  the  relationship  of  the  mind  of 
man  to  the  Intelligence  whence  issued  the  Universe. 

Every  great   scientific  generalization  will  illus- 
trate   more    or   less    clearly   the    principles    here 
stated.     It  is  true  tha^  many  minds  fre-  miration  of 
quently  concur  in  developing  one  grand  the  method< 
idea,  and  the  evolution  may  occupy  so  long  an  in- 
terval of  time  that  the  new  truth  appears  to  be  the 
growth  of  an  age,  rather  than  the  gift  of  any  one 
man.     Yet  it  is  possible  in  almost  every  case   to 
trace  the  successive  steps  of  the  discovery.    This  is 


252  RELIGION   AND    CHEMISTRY.  [LECT.  VIH. 

especially  true  of  the  law  of  gravitation.  Whether 
the  first  idea  was  suggested  to  Newton  by  the  fall 
of  an  apple,  it  is  not  important  to  inquire  ;  but  the 
popular  anecdote  illustrates  the  nature  of  the  origi- 
nal thought,  which  was  undoubtedly  sudden  and 
intuitive,  although,  as  Newton  has  himself  express- 
ly stated,  it  was  the  result  of  analogical  reasoning. 
The  conception  once  formed,  the  work  of  verifica- 
tion was  long  and  laborious,  and  the  results  were 
at  first  so  unsatisfactory,  that  Newton  at  one  time 
abandoned  his  theory  altogether,  as  unsupported  by 
observation.  It  was  not,  indeed,  until  a  new  arc 
of  the  meridian  had  been  measured  by  Picard  in 
France  —  several  years  after  the  first  conception  — 
that  the  facts  were  found  to  agree  even  approxi- 
mately with  the  theory,  and  astronomers  have  been 
occupied  ever  since  in  verifying  the  grand  thought. 
The  same  general  facts  reappear  in  the  case  of  the 
wave-theory  of  light,  first  conceived  by  Huyghens 
and  subsequently  verified  by  the  successive  discov- 
eries of  Malus,  Fresnel,  and  Young;  and  we  may 
lay  it  down  as  an  almost  universal  principle,  that 
scientific  truth  is  discovered  through  analogy  and 
verified  by  comparison  with  the  facts  of  nature. 

If  now  you  will  turn  to  the  great  central  truth 
of  natural  religion,  you  will  find  that  it  has  as  good 
credentials  as  the  best  established  laws  of 


tai  truth  of      science.     We  have  first  the  conception,  — 

natural  religion  . 

rests  on  the      not  only  the  conception  of  a  few  highly 


gifted  minds,  but  the  universal  conception 
science.          0£  mankin(i.     ^re  find  afterwards  this  con- 


LECT.V1IL]    ARGUMENT   FROM   SPECIAL  ADAPTATIONS.        253 

ception  verified,  —  not  only  in  the  history  of  the 
race,  but  also  in  the  experience  of  each  individual 
man,  and  moreover  the  conception  is  apparently  in- 
tuitive in  every  mind.  Even  if  the  sceptic  denies 
the  reality  of  both  special  and  general  providence, 
he  must  admit  that,  as  the  almost  universal  rule, 
both  history  and  experience  have  only  served  to 
confirm  and  strengthen  the  religious  idea. 

We  "return  now  to  the  remark  above  quoted,  bet- 
ter able  both  to  appreciate  the  truth  it  contains 
and  to  unmask  the  fallacy  it  conceals.  A  large  part 
of  the  results  of  science  may  be  demonstrated,  but 
only  such  truths  as  are  already  contained  in  the 
premises  on  which  the  demonstration  rests  are  capa- 
ble of  this  absolute  proof;  and  these  are  in  all  cases 
reached  by  the  human  intelligence  working  on  its 
own  definitions  and  processes  of  thought,  and  this, 
too,  even  when  the  theoretical  truth  is  afterwards 
found  realized  in  nature.  The  highest  forms  of 
scientific  truth  are  not  capable  of  demonstration, 
and  rest  only  on  probable  evidence,  although  the 
probability  in  their  favor  is  so  great  as  to  beget  the 
highest  degree  of  moral  certainty.  In  like  manner, 
a  great  part  of  the  truths  of  religion  must  be  ac- 
cepted on  faith ;  but  then  the  evidence  in  favor  of 
the  great  fundamental  truth  of  natural  religion  is 
as  strong  as  the  evidence  for  the  law  of  gravita- 
tion, and  the  certainty  is  as  great.  More-  province 
over,  faith  is  not  peculiar  to  religion.  All  of  faith> 
our  knowledge  not  the  result  of  personal  observa- 
tion and  investigation  is  held  on  faith,  that  is,  on 


254  RELIGION   AND    CHEMISTRY.  [LECT.  VIII. 

trust  in  other  men,  and  absolutely  all  knowledge  is 
held  on  trust  in  the  authority  of  our  own  powers. 
Much  of  the  knowledge  which  we  hold  without  ques- 
tion, it  is  utterly  beyond  the  capacity  of  our  own 
intellects  to  verify,  and  moreover,  no  one  doubts 
the  existence  of  truths  which  now  lie  beyond  the 
scope  of  the  most  gifted  genius,  but  which  hereafter 
may  be  attained  by  man.  The  scientific  truths 
which  it  is  not  essential  for  us  to  know  are  left  in 
the  dark  on  purpose  to  stimulate  study,  and  thus 
to  educate  the  human  race.  Keligious  truths,  on 
the  other  hand,  it  is  essential  for  us  to  know,  and, 
since  they  in  like  manner  transcend  our  present 
powers,  they  have  been  specially  revealed.  We  are 
called  upon  to  accept  them  on  sufficient  evidence, 
and  this  is  all  that  is  meant  by  faith.  Faith,  then,  is 
as  truly  a  ground  of  belief  in  science  and  in  com- 
mon life  as  it  is  in  religion,  and  it  occupies  a  more 
important  place  in  religion  only  because  religious 
truth  is  itself  so  important,  and  so  greatly  tran- 
scends, in  its  essence,  our  limited  human  faculties. 

Our  reply,  then,  to  the  first  position  of  the  scep- 
tic is  this.  Your  objections  apply  as  well  to  all 
knowledge  as  they  do  to  religious  truth,  and,  if  you 
are  consistent  with  yourself,  you  must  reject  the 
evidences  of  science  as  well  as  the  evidences  of 
religion.  As  we  are  not  prepared  to  go  this  length, 
we  shall  with  equal  consistency  hold  to  both.  It  is 
but  justice  to  state  that  Hume,  the  most  philosophi- 
cal of  the  sceptics,  pushed  his  speculations  to  their 
necessary  consequences,  and  denied  the  existence 


LECT.VIH.]     AKGUMENT   FROM   SPECIAL   ADAPTATIONS.        255 

of  matter  and  spirit  alike.  But  although  from  its 
very  boldness  difficult  to  refute,  this  form  of  scepti- 
cism is  by  no  means  the  most  dangerous  ;  for  in  the 
present  age  of  the  world  a  system  of  philosophy  is 
not  likely  to  gain  many  adherents  which,  in  the  first 
article  of  its  creed,  utterly  shocks  all  human  self- 
conceit,  by  declaring  that  man  neither  knows  nor 
can  know  anything  with  certainty. 

In  the  second  place,  the  sceptic  attacks  the  argu- 
ment for  design  by  setting  up  a  theory  of  his  own 
to  explain  the  origin  of  the  universe.  He  Absolute 
tacitly  admits  that  the  burden  of  proof  is  materialism- 
with  him,  and  that,  if  he  rejects  the  popular  belief, 
he  is  bound  to  show  how  this  cosmos  might  have 
been  issued  without  intelligence  and  without  a  God. 
This  he  attempts  to  do,  and  the  result  is  nearly  as 
many  theories  as  there  have  been  strong  scientific 
intellects  in  the  world  united  with  unbelieving 
hearts.  To  refute  each  of  these  theories  in  detail 
would  be  a  labor  like  that  of  Hercules  in  slaying 
the  Lernsean  Hydra  ;  for  until  Almighty  Power 
shall  sear  the  foul  sore  from  which  the  whole  brood 
proceeds,  their  unholy  heads  will  start  up  more  rap- 
idly than  they  can  be  cut  down.  The  most  daring 
theories  of  this  kind  are  those  of  the  German  mate- 
rialists of  the  present  day.  As  much  as  they  may 
differ  among  themselves  in  regard  to  details,  the 
boldest  of  these  speculators  agree  in  maintaining 
that  absolutely  nothing  exists,  or  ever  has  existed, 
except  matter  and  motion ;  that  matter  in  its  es- 
sence is  uncreated  and  eternal  ;  that  motion  is  self- 

17 


256  RELIGION   AND    CHEMISTRY.  [LECT.  VIII. 

sustained ;  that  mind  is  only  a  mode  of  motion,  and 
that  all  the  phenomena  both  of  matter  and  of  mind 
are  the  working  out  of  an  inexorable  necessity. 
Hence  they  conclude  that  religion  is  a  fable,  and 
immortality  a  dream. 

Here  is  atheism.  This  is  the  natural  fruit  of 
materialism ;  and  we  are  glad  that  it  has  ripened, 
that  men  may  see  how  disgusting  and  revolting  it 
is,  and  how  corrupt  the  tree  must  be  which  can 
bear  such  fruit.  We  are  glad  that  men  should 
know  what  must  be  the  result  of  all  their  vain 
speculation  and  the  seeking  after  false  gods.  The 
theory  is  perfectly  consistent  with  itself,  and  an 
absolute  necessity  if  nature  be  divorced  from  its 
Creator ;  for  all  philosophy  has  proved  that  either 
the  theory  of  the  Christian,  or  this  theory  of  the 
materialist,  with  all  its  enormity,  must  be  true. 
There  is  no  half-way  halting-place  between.  This 
course  of  Lectures  has  been  a  continued  protest 
against  the  materialist's  interpretation  of  nature, 
and  I  have  not  another  word  to  add ;  for  if  a  man 
wishes  to  believe  that  his  purest  loves  and  his  holi- 
est affections  are  only  motions  of  brain-particles, 
nothing  that  can  be  said  would  have  the  slightest 
weight.  If  he  has  not  already  the  refutation  in  his 
own  consciousness  of  being,  human  power  cannot 
aid  him ;  no  philosophy  can  extricate  him  from 
the  slough.  "  Ephraim  is  joined  to  idols :  let  him 
alone." 

It  is  seldom,  however,  that  materialism  shows  its 
revolting  features  among  us.  It  is  too  cunning 


LECT.  VIII.]    ARGUMENT   FROM   SPECIAL   ADAPTATIONS.        257 

and  too  cautious.  It  always  appears  disguised, 
and  is  for  this  reason  far  more  seductive.  It  pre- 
sents the  attraction  of  great  learning;  and 

.  .  Materialism 

of  great  apparent  profundity,  entangling  m  us  more 
many  in  its  meshes  before  they  are  r 
aware  of  their  danger.  It  does  not  deny  the  real- 
ity of  the  human  intellect,  but,  on  the  contrary, 
takes  pride  in  its  authority  and  power.  It  even 
admits  the  evidence  of  design,  but  at  the  same 
time  insidiously  undermines  all  religious  belief; 
not  so  much,  however,  by  what  it  declares,  as  by 
what  it  leaves  to  be  inferred ;  not  so  much  by  the 
doctrines  it  inculcates,  as  by  the  spirit  it  keeps  alive 
and  fosters.  In  this  refined  form,  materialism  is  by 
far  the  most  prevalent  phase  of  the  unbelief  of  our 
time,  and  it  is  difficult  to  meet  chiefly  on  account 
of  its  very  vagueness  and  simulation.  It  lives  al- 
most entirely  in  the  ever-changing  theories  and 
speculations  of  science,  which  it  utterly  misinter- 
prets and  misapplies,  forgetting  that  they  are  mere- 
ly provisional  expedients,  which  the  next  wave  of 
advancing  knowledge  may  wash  away.  Develop- 
ment is  the  pet  word  of  its  philosophy,  and  it 
constantly  aims  to  show  how  the  whole  Development 
scheme  of  nature,  with  all  its  adaptations,  theories- 
might  have  been  evolved  through  the  concurrent 
action  of  various  unintelligent  causes  alone.  As 
it  attacks  the  argument  for  design  on  scientific 
grounds,  it  becomes  the  duty  of  the  student  of  na- 
ture to  expose  its  errors.  It  is,  however,  a  most 
protean  antagonist,  and  no  sooner  is  it  defeated  in 


258  RELIGION   AND    CHEMISTRY.  [LECT.  VIII. 

one  form  than  it  reappears  in  another.  Every  new 
development  theory  in  any  department  of  science 
furnishes  it  with  fresh  food.  For  a  long  time  the 
famous  nebular  hypothesis  of  Laplace  supplied  it 
with  abundant  nourishment,  and  quite  recently  it 
has  taken  a  fresh  start,  and  grown  most  vigorously, 
on  Mr.  Darwin's  very  ingenious  book  entitled  "  The 
Origin  of  Species."  But  these  are  only  two  exam- 
ples of  a  large  number  of  similar  works,  which,  be- 
ing less  able  and  less  original,  have  had  their  day 
and  been  forgotten. 

The  danger  of  these  works  lies  not  so  much  in 
what  they  actually  contain,  as  in  their  general 
The  danger  of  tendency;  not  so  much  in  the  theories 
such  theories.  of  their  authors,  as  in  the  wrong  conclu- 
sions which  will  inevitably  be  drawn  from  them, 
and  to  which  in  many  cases  they  logically  lead. 
Darwin,  for  example,  professes  to  show  that  all  the 
living  forms  of  plants  and  animals,  man  included, 
have  been  during  the  geological  ages  slowly  devel- 
oped from  a  few  germs,  or  possibly  from  only  one,  by 
the  action  of  a  principle  which  he  calls  the  "  law  of 
natural  selection"  and  he  sustains  the  hypothesis  by 
a  most  formidable  array  of  experiments  and  facts. 
Such  a  theory  as  this,  ingenious  if  not  true,  pro- 
fessing to  explain  one  of  the  greatest  mysteries, 
and  presented  in  a  fascinating  style,  finds  its  con- 
verts everywhere,  and  this,  too,  on  grounds  entirely 
independent  of  its  scientific  merit.  That  very  same 
noble  aspiration  which  leads  men  to  imperil  even 
life  itself  in  investigating  the  secrets  of  nature, 


ARGUMENT   FROM   SPECIAL   ADAPTATIONS.        259 

makes  them  also  ready  to  lend  a  willing  ear  to  any 
theory  which  professes  to  explain  the  mystery  of 
creation.  Hence  the  reason  why  works  like  the 
Vestiges  of  Creation,  and  those  just  mentioned, 
captivate  and  injure  so  many.  If  they  merely 
stimulated  curiosity,  and  led  to  study,  no  one  could 
object  to  their  influence,  however  erroneous  he 
might  think  their  philosophy.  But,  unfortunately, 
most  readers,  of  whom  it  is  no  disparagement  to 
say  that  they  are  not  in  a  condition  to  weigh  the 
evidence,  accept  the  theory  without  examination, 
and,  if  sceptically  inclined,  their  whole  belief  in  an 
overruling  Providence  is  shaken  to  its  base. 

It  is  in  vain  to  urge  that  these  theories  may  be 
consistent  with  a  pure  faith ;  for  as  long  as  they  are 
not  so  regarded  by  the  popular  mind,  —  which  in- 
variably appeals  to  them  as  proofs  of  materialism,  — 
the  evil  which  they  cause  is  not  remedied.  It  may 
be  said,  and  said  with  some  justice,  that  a  writer 
cannot  be  blamed  for  the  abuse  of  his  DUty0f 
theory;  but  it  must  be  admitted  that  scientific men- 
the  abuse  is  a  great  evil,  and  an  author,  if  he  be  a 
religious  man,  is  bound  to  guard  against  it  by  every 
means  in  his  power.  We  should  be  very  slow  to 
charge  any  man  with  infidelity,  for  we  know  how 
often  the  human  mind,  in  its  eccentricities  and  in- 
consistencies, has  united  a  true  faith  to  the  most 
sceptical  and  subversive  speculations.  But  we  do 
say,  that  the  least  a  Christian  philosopher  can  do 
for  his  faith  is  to  give  such  a  tone  and  spirit  to  his 
work  as  to  render  misinterpretation  impossible ;  and 


260  RELIGION   AND    CHEMISTRY.  [LKCT.  VIII. 

if  he  neglects  to  do  this,  he  has  no  right  to  com- 
plain if  his  own  opinions  are  misjudged.  It  is  to  no 
purpose  to  reply,  that  religion  is  out  of  place  in  a 
work  on  science ;  for  the  class  of  books  to  which  we 
refer  are  not  addressed  to  scholars,  but  to  the  gen- 
eral reading  public,  and,  in  some  cases  at  least,  they 
are  appeals  from  the  settled  convictions  of  thinking 
men  to  the  unformed  opinions  of  the  popular  mind. 
A  scientific  man  who  presents  his  theories  in  an  at- 
tractive form  to  the  public,  before  they  have  passed 
the  ordeal  of  criticism  by  his  peers,  appeals  to  a 
court  which  has  no  right  to  judge,  and  whose 
opinion  would  be  worth  nothing  if  given.  Eeal 
and  permanent  injury  may  be  thus  inflicted,  and 
an  author  has  no  right  to  take  advantage  of  the 
ignorance  of  his  readers.  If  he  does  this  to  gain  a 
transient  notoriety,  it  may  be  a  pardonable  error ; 
but  I  cannot  find  language  sufficiently  strong  to 
express  my  condemnation  of  those  popular  writers 
who  insidiously  undermine  the  faith  of  the  commu- 
nity by  imposing  crude  speculations  on  their  igno- 
rance. 

I  shall  not  attempt  to  discuss  the  intrinsic  value 
of  the  various  theories  of  development.  They  have 
all  been  judged  in  a  competent  court,  and  the  al- 
most unanimous  verdict  of  scientific  men  has  been 
simply  "not  proven."  This  is  true  even  of  the 
nebular  hypothesis  of  Laplace,  which  many  astrono- 
mers are  inclined  to  accept  as  a  convenient  theory, 
a  sort  of  scaffolding  for  their  science,  but  as  nothing 
more  durable ;  and  still  more  is  it  true  of  the  differ- 


LKcr.Vm.]    ARGUMENT   FROM   SPECIAL   ADAPTATIONS.        261 

ent  theories  which  from  time  to  time  have  been 
advanced  to  explain  the  origin  of  species.  Man 
will  not  be  likely  to  disown  his  divine  parentage 
until  some  at  least  of  the  links  which  connect  him 
with  the  brutes  can  be  pointed  out.  If  any  theory 
of  development  be  true,  there  must  have  been  an 
indefinite  number  of  links  between  the  noblest  chim- 
panzee and  the  most  degraded  Hottentot,  and  yet 
the  progressionists,  Darwin  included,  have  failed  to 
discover  a  single  one. 

But  leaving  to  those  who  are  competent  judges 
the   task   of  exposing   the   unsoundness   of  these 
speculations,  let   us   inquire    what  bear-  Development 
ing  they  have   on  the   evidence   of  de-  theories  do  not 

impair  the  ar- 

sign.      I   answer,    absolutely    none.     As- 


suming  that  Mr.  Darwin  could  establish  d 
his  peculiar  theory  in  all  its  generality,  —  and  I 
have  no  doubt  that  it  has  an  element  of  truth, 
—  it  would  not  impair  the  evidence  of  design  in 
the  slightest  degree,  and  the  same  is  true  of  any 
development  theory  whatsoever  short  of  absolute 
materialism.  Those  persons  who  imagine  that  they 
overthrow  natural  religion,  fall  into  a  capital  error. 
It  requires  manifestly  the  same  infinite  intelligence 
to  create  a  universe  by  a  process  of  development 
as  by  a  single  creative  fiat.  Your  belief  that  the 
beautiful  piece  of  mechanism  standing  on  your 
mantel-shelf  was  made  by  an  intelligent  man,  would 
not  be  impaired  if  you  were  told  that  the  artist  was 
employed  several  years  in  its  construction.  The 
evidence  of  design  in  the  clock  is  in  its  beautifully 


262  RELIGION   AND    CHEMISTRY.  [LECT.  VIE. 

adjusted  mechanism.  The  evidence  of  design  in 
nature  is  in  the  wonderful  adaptation  of  its  parts. 
We  can  easily  go  back  in  the  geological  records  to 
the  time  when  the  present  order  of  nature  did  not 
exist,  and  the  fact  that  the  innumerable  forms  of 
organic  life,  with  the  adaptations  of  currents,  soil, 
and  climate  essential  to  their  being,  have  been  de- 
veloped out  of  the  conditions  which  existed  on  the 
globe  during  the  coal  epoch,  is  no  less  an  evidence 
of  design,  than  the  fact  that  the  clock  was  developed 
out  of  the  crude  iron  and  brass  used  in  its  con- 
struction. 

"  We  lament,"  says  a  recent  writer,  "  to  see  the 
question  between  a  sudden  and  a  gradual  genesis  of 
organic  types  discussed  on  both  sides  —  not,  indeed, 
by  the  principals  in  the  dispute,  but  by  secondary 
advocates  —  too  much  as  if  it  were  a  question  be- 
tween God  and  no  God.  In  not  a  few  of  the  pro- 
gressionists the  weak  illusion  is  unmistakable,  that 
with  time  enough  you  may  get  everything  out  of 
next  to  nothing.  Grant  us,  they  seem  to  say,  any 
tiniest  granule  of  power,  so  close  upon  zero  that 
it  is  not  worth  begrudging ;  allow  it  some  trifling 
tendency  to  infinitesimal  increment ;  and  we  will 
show  you  how  this  little  stock  became  the  cosmos 
without  ever  taking  a  step  worth  thinking  of,  much 
less  constituting  a  case  for  design.  The  argument 
is  a  mere  appeal  to  an  incompetency  in  the  human 
imagination,  in  virtue  of  which  magnitudes  evading 
conception  are  treated  as  out  of  existence,  and  an 
aggregate  of  inappreciable  increments  is  simulta- 


LECT.  VHL]     ARGUMENT   FROM   SPECIAL   ADAPTATIONS.        263 

neously  equated  in  its  cause  to  nothing,  in  its  ef- 
fect to  the  whole  of  things.  You  manifestly  want 
the  same  causality  whether  concentrated  on  a  mo- 
ment or  distributed  through  incalculable  ages,  only, 
in  drawing  upon  it,  a  logical  theft  is  more  easily 
committed  piecemeal  than  wholesale.  Surely  it  is 
a  mean  device  for  a  philosopher  thus  to  crib  causa- 
tion by  hair-breadths,  to  put  it  out  at  compound  in- 
terest through  all  time,  and  then  disown  the  debt ; 
and  it  is  in  vain,  after  all ;  for  dilute  the  intensity 
and  change  the  form  as  you  will  of  the  Power  that 
has  issued  the  universe,  it  remains,  except  to  your 
subjective  illusion,  nothing  less  than  infinite,  and 
nothing  lower  than  divine." 

So  far  as  the  genesis  of  nature  is  concerned,  I  am 
not  sure  that  a  development  theory  is  not  the  more 
probable.  At  all  events,  it  is  a  question  of  facts  to 
be  decided  by  scientific  investigation,  and  by  that 
alone.  Let  us  insist  that  all  theories  of  cosmogony 
shall  be  judged  on  their  own  merits ;  but  let  us 
also  insist  that  they  shall  be  kept  within  their  own 
sphere,  and  not  allowed  to  have  a  voice  in  ques- 
tions on  which  they  have  absolutely  no  bearing. 
Again  I  repeat,  no  development  theory  can  impair 
the  evidence  of  design ;  for  that  evidence  is  based  on 
facts  wholly  independent  of  any  theory  of  cosmog- 
ony, and  to  which  all  theories  must  conform.  If 
they  do  not,  they  will  inevitably  fall.  The  difficulty 
to  my  mind  in  Mr.  Darwin's  particular  theory  is  not 
in  its  development  feature,  but  in  the  fact  that  he 
refers  the  development  to  what  I  can  understand 


264  RELIGION   AND    CHEMISTRY.  [LECT.  VIH. 

only  as  an  unintelligent  cause.  He  may  be  able  to 
give  a  different  interpretation  to  his  theory,  and  I 
greatly  regret  that  he  does  not ;  but  unless  he  can 
show  that  it  is  consistent  with  the  action  of  an  in- 
telligent First  Cause,  it  will  soon  be  forgotten,  like 
those  that  have  gone  before  it.  This  is  the  crite- 
rion by  which  all  such  theories  are  finally  judged, 
after  the  excitement  of  the  controversy  by  which 
they  are  heralded  has  passed,  and  after  the  common 
sense  of  mankind  has  settled  down  upon  its  sober 
second- thought.  That  they  have  an  injurious  bear- 
ing while  they  last,  is  frequently  more  the  fault  of 
the  secondary  advocates  than  of  the  principals  in 
the  dispute,  and  we  must  not  expect  to  cure  the  evil 
by  indiscriminate  censure  or  by  social  excommuni- 
cation. So  long  as  man  thinks,  he  will  speculate  ; 
and  I  rejoice  that  neither  political  nor  ecclesiasti- 
cal tyranny  can  touch  this  prerogative  of  free 
thought.  The  true  remedy  consists  in  exposing 
the  fallacy  of  the  shallow  philosophy  which  is  so 
ready  to  bring  forward  these  crude  speculations  as 
proofs  of  materialism,  and  also  in  diffusing  among 
educated  people  more  spiritual  views  of  nature 
and  its  laws. 

To  this  subject  I  shall  return  in  the  next  Lecture. 
But  so  far  as  the  argument  for  design  is  concerned, 
all  these  considerations  are  unnecessary.  The  evi- 
dence is  so  ample  and  broad,  that  we  can  afford  to 
waive  all  that  part  of  it  which  has  been  called  in 
question  by  the  progressionists,  without  weakening 
in  the  slightest  degree  the  force  of  the  argument. 


LECT.  VHL]    ARGUMENT  FEOM   SPECIAL  ADAPTATIONS.        265 

Before  the  first  organic  cell  could  exist,  and  before 
Mr.  Darwin's  principle  of  natural  selection  could 
begin  that  work  of  unnumbered  ages  which  was 
to  end  in  developing  a  perfect  man,  nay, 
even  before  the  solid  globe  itself  could  of  design  m 
be  condensed  from  Laplace's  nebula,  the  ^anyae" 
chemical  elements  must  have  been  creat-  riesofdevel- 

opinent. 

ed,  and  endowed  with  those  properties  by 

which  alone  the  existence  of  that  cell  is  rendered 

possible. 

But  although,  for  the  sake  of  argument,  we  might 
yield  to  the  progressionists  all  those  examples  of 
adaptation  which  they  claim  to  explain  by  their 
theories,  such  a  concession  is  really  of  no  value. 
The  parts  of  nature,  as  we  have  seen,  are  so  inti- 
mately linked  together  that,  if  there  is  design  any- 
where, there  is  design  everywhere ;  and  as  the 
structure  of  the  human  body  is  prefigured  by  the  ear- 
liest vertebrate  forms  buried  in  the  geological  strata, 
so,  and  as  unquestionably,  the  whole  scheme  of 
organic  life  is  prefigured  in  the  gases  composing  the 
atmosphere.  If,  therefore,  I  have  proved  that  there 
is  evidence  of  design  in  the  constitution  of  the  at- 
mosphere, I  have  also  proved  that  the  whole  scheme 
of  nature  is  the  result  of  Divine  Intelligence,  and 
that  the  great  argument  of  natural  theology  rests 
on  a  basis  which  no  present  theories  *  of  develop- 

*  We  of  course  refer  only  to  such  theories  and  speculations  as  are 
based  on  observed  facts ;  for  no  others  are  worthy  of  serious  consid- 
eration. Science  has  not  as  yet  gone  one  step  behind  the  chemical  ele- 
ments, and  until  it  has,  no  speculations  in  regard  to  a  primordial  condi- 
tion of  matter  can  have  any  bearing  on  our  subject. 


266  RELIGION    AND    CHEMISTKY.  [LECT.  VHI. 

merit  can  touch.  To  show  that  there  is  evidence 
of  design  in  these  stones  of  nature's  edifice  has  been 
the  chief  object  of  this  course  of  Lectures.  It  has 
been  my  constant  aim  to  set  forth  in  a  clear  light 
the  startling  fact  that  the  foot-prints  of  the  Creator 
are  nowhere  more  plainly  visible  than  on  that  very 
matter  which  the  materialists  so  vainly  worship, 
and  if  I  have  thus  been  able  to  remove  doubts 
from  the  mind  of  any  honest  seeker  after  God,  I 
shall  feel  that  my  labor  has  not  been  lost. 

But  however  earnest  our  purpose  or  sincere  our 
convictions,  the  spectres  of  our  doubts  will  some- 
times return,  and  hover  around  these  evidences  of 
our  faith.  Treat  them  not  lightly  either  in  yourself 
or  in  those  you  love.  Kespect  all  honest  doubts ; 
for  it  is  the  noblest  natures  which  feel  them  and 
suffer  most.  His  must  be  a  dull  heart  which  is  not 
sometimes  appalled  by  the  mystery  of  our  being. 
Eemember,  however,  that  these  doubts  are  from 
within,  not  from  without.  They  are  the  offspring  of 
your  fears,  and  not  of  your  science.  The  evidence 
is  ample.  It  is  more  faith  that  you  need.  Fight 
then  these  spectres  of  your  mind  as  you  would  the 
enemies  of  your  peace,  not  with  doubtful  disputa- 
tions, but  with  earnest  thought  and  prayer,  and 
Power  shall  be  with  you 

"  in  the  night, 

Which  makes  the  darkness  and  the  light, 
And  dwells  not  in  the  light  alone." 


LECTUEE    IX. 

ARGUMENT   FROM   GENERAL   PLAN. 

IT  has  been  my  object  in  the  previous  Lectures 
of  this  course  to  develop  before  you  the  great  argu- 
ment of  Natural  Theology  as  it  is  presented  by  the 
atmosphere.  I  have  endeavored  to  show  that  there 
is  abundant  evidence  of  design,  even  in  the  proper- 
ties of  the  chemical  elements,  and  hence  that  the  ar- 
gument rests  upon  a  basis  which  no  present  theories 
of  development  can  shake.  Having  dwelt  upon  the 
argument  from  special  adaptations  at  as  great  length 
as  my  time  will  permit,  I  wish  in  my  Lecture  of  this 
evening  to  ask  your  attention  to  another  class  of 
evidences  of  the  Divine  attributes,  which,  although 
less  conspicuous,  may  be  even  more  impressive  to 
some  minds  than  those  we  have  studied.  The  indi- 
cations of  an  Infinite  Intelligence  are  not  only  to  be 
found  in  the  adaptations  of  nature,  but  they  also  ap- 
pear, and  still  more  visibly,  in  the  grand  laws  by 
which  the  whole  material  universe  is  directed. 

I  am  well  aware  that  the  laws  of  nature,  so  far 
from  being  regarded  as  evidences  of  the  existence 
of  a  beneficent  God,  are  felt  by  many  minds  to  be 
actual  hinderances  to  their  faith.  They  are  thought 
to  give  to  the  whole  scheme  of  nature  a  mechanical 
aspect,  and  to  be  inconsistent  with  belief  in  a  su- 


268  RELIGION   AND    CHEMISTRY.  [LECT.  IX. 

perintending  Providence.  I  also  know  that  there 
are  many  scientific  men  who  regard  the  laws  of  na- 
ture as  the  manifestation  of  blind  physical  forces, 
and  who  recognize  a  Providence,  if  at  all,  only  in 
the  very  few  recorded  instances  where  the  normal 
action  of  these  forces  has  been  averted  by  a  special 
miraculous  interposition.  But  even  admitting  this 
philosophy,  still  I  think  it  will  appear  that  these 
laws  bear  so  conspicuously  the  marks  of  Intelli- 
gence, and  are  so  analogous  to  the  results  of  human 
thought,  that  we  .cannot  resist  the  conclusion  that 
they  were  originally,  at  least,  ordained  by  an  intel- 
ligent Creator,  or  in  other  words  that  the  laws  of 
nature  are  the  thoughts  of  God.  For  myself,  I  re- 
gard the  laws  of  nature  as  the  most  direct  evidence 
possible  of  Infinite  wisdom,  and  it  will  be  my  object 
to  show  that  this  opinion  is  sustained  by  the  strong- 
est analogies. 

Kegarded  from  a  scientific  point  of  view,  physical 
laws  are  merely  our  human  expressions  of  that 
Definition  of  order  which  we  discover  in  the  material 
physical  la^.  universe.  In  its  highest  form,  the  law  is 
capable  of  a  precise  quantitative  statement,  and 
gives  the  bases  for  mathematical  calculation  and 
prediction.  Thus  the  law  of  gravitation  enables 
the  astronomer  to  calculate  what  will  be  the  posi- 
tion of  the  bodies  of  the  solar  system  at  any  future 
epoch,  and  to  predict  almost  to  the  very  second  the 
exact  time  when  an  eclipse  will  begin,  and  what 
will  be  the  precise  path  of  its  shadow  over  the 
earth.  The  greater  part  of  the  laws  of  nature  do 


LECT.IX.]  ARGUMENT   FROM   GENERAL   PLAN.  269 

not,  however,  admit  of  precise  mathematical  state- 
ment, and  are  merely  the  expressions  of  the  order 
which  has  been  observed  in  the  phenomena  of  na- 
ture, whether  in  respect  to  form,  in  respect  to  num- 
ber, or  in  any  other  particular.  It  is  convenient  to 
distinguish  these  merely  phenomenal  laws  from  the 
higher  class,  which  are  usually  called  dynamical 
laws ;  but  the  distinction  is  an  artificial  one ;  for  it 
is  probable,  at  least,  that  in  all  cases  the  phenome- 
nal laws  are  merely  the  phases  of  some  higher  dy- 
namical law  not  yet  discovered.  Moreover,  if  we 
believe  that  all  phenomena  are  direct  manifesta^ 
tions  of  the  Divine  Will,  then  there  is  no  law  apart 
from  God.  His  action  is  not  necessitated  or  pre- 
scribed by  any  conditions,  even  although  imposed 
by  Himself.  He  is  constantly  acting  in  nature, 
consciously  and  freely ;  but  He  acts  uniformly, 
consistently,  and  with  a  plan,  because  He  is  om- 
niscient and  omnipotent.  Man  acts  with  incon- 
stancy, because  he  is  a  finite  being,  and  must  be 
guided  by  probabilities ;  but  with  God,  who  seeth 
the  end  from  the  beginning,  there  is  no  "  variable- 
ness, neither  shadow  of  turning." 

The  whole  material  universe  may  then  be  re- 
garded as  the  manifestation  of  one  grand  compre- 
hensive creative  thought,  which  God  is  slowly  work- 
ing out  in  nature.  To  study  this  thought  in  all  its 
details  is  the  prerogative  of  man,  and  this  study 
has  been  the  appointed  means  of  cultivating  his  in- 
tellect and  elevating  his  condition.  From  time  to 
time  the  more  gifted  students  have  caught  glimpses 


2  TO  RELIGION   AND    CHEMISTRY.  [LECT.  IX. 

of  parts  of  the  grand  thought,  and  these  glimpses 
we  call  laws ;  but  even  the  law  of  gravitation,  the 
most  perfect  of  all,  is  felt  to  be  but  a  partial  truth, 
and  all  eternity  will  be  required  to  comprehend 
the  scheme.  Let  us  now,  in  order  to  elucidate  and 
confirm  this  simple  doctrine,  compare  some  of  the 
laws  of  nature  with  the  results  of  human  thought, 
and,  whatever  may  be  our  theory  of  causation,  we 
cannot  but  be  impressed  with  the  striking  analogy 
between  the  two. 

The  idea  of  symmetry  is  inherent  in  every  hu- 
man mind.  It  may  be  more  or  less  cultivated  by 
The  idea  of  experience,  but  the  germs  of  the  idea  are 
symmetry.  found  even  in  the  savage.  However  rude 
his  condition,  man  is  pleased  with  a  symmetrical 
disposition  of  objects,  and  his  taste  is  offended  when 
the  laws  of  symmetry  are  grossly  violated,  although 
he  may  have  no  name  for  the  idea.  Corresponding 
with  this  idea  in  our  minds,  we  find  symmetry  every- 
where in  nature.  The  parts  of  an  animal  are  sym- 
metrically arranged  round  the  body,  and  the  leaves 
of  a  plant  are  symmetrically  disposed  around  the 
stem,  but  nowhere  in  nature  is  the  idea  of  sym- 
metry so  fully  developed  as  in  the  mineral  kingdom. 

Almost  every  solid  substance,  when  slowly  de- 
posited from  a  liquid  or  aeriform  condition,  assumes 
a  definite  symmetrical  shape  which  is  pe- 
culiar to  the  substance.  Such  symmetri- 
cal forms  are  called  crystals,  and  the  process  by 
which  they  are  obtained  is  called  crystallization. 
Freedom  of  motion  —  such  as  the  particles  of  mat- 


LECT.  IX.]          ARGUMENT   FROM   GENERAL   PLAN.  2?1 

ter  have  in  the  fluid  condition  —  is  an  essential 
condition  of  crystallization.  Moreover,  as  the  sub- 
stance becomes  solid,  the  particles  must  have  suf- 
ficient time  to  arrange  themselves  in  accordance 
with  the  tendency  of  the  molecular  forces,  and  the 
longer  the  time  occupied  in  the  process  of  crystal- 
lization, the  more  perfect  we  find  the  crystals.  The 
perfect  crystals  represent  the  natural  condition  of  a 
substance,  and  the  peculiar  form  is  the  most  essen- 
tial and  characteristic  of  all  its  properties. 

Crystals  are  always  polyhedrons,  that  is,  solids 
bounded  by  plane  faces,  and  these  faces  are  sym- 
metrically disposed  about  certain  straight  Sy8tem9of 
lines  called  axes.  Moreover,  it  has  been  crystals- 
observed  that,  although  we  might  conceive  of  an 
infinite  number  of  systems  of  straight  lines,  there 
are  only  six,  or  at  most  seven,  such  systems  in  na- 
ture, and  all  crystals,  with  possibly  one  exception, 
are  formed  by  the  symmetrical  disposition  of  planes 
around  one  or  the  other  of  the  six  systems  repre- 
sented in  Fig.  2.  The  first  five  of  these  systems 
have  each  three  axes,  and  the  last  alone  has  four. 
In  No.  1  the  three  axes  are  of  equal  length  and  at 
right  angles  to  each  other.  This  arrangement  is 
called  the  monometric  system,  from  two  Greek  words 
signifying  one  measure.  In  No.  2  the  axes  are  all 
at  right  angles,  as  before ;  but  the  vertical  axis  is 
either  longer  or  shorter  than  the  other  two.  This 
is  called  the  dimetric  system,  —  two  measures.  In  No. 
3  the  axes  are  still  at  right  angles,  but  of  unequal 
length.  This  is  called  the  trimetric  system,  —  three 

18 


272 


RELIGION   AND    CHEMISTRY. 


[LECT.  IX. 


Fig.  2. 

measures.  In  No.  4  all  the  axes  are  of  unequal 
length,  as  in  the  last,  and  the  two  horizontal  axes 
are  at  right  angles.  The  vertical  axis  is  also  at 
right  angles  to  one  of  the  horizontal  axes,  but  it  is 
inclined  to  the  other.  Hence  the  sys- 
tem is  called  the  monoclinic  system,  — 
one  inclination.  In  No.  5  the  three 
axes  are  all  unequal  in  length,  and  all 
at  oblique  angles  with  one  another. 
Hence  the  system  is  called  the  triclinie 
system,  —  three  inclinations.  Lastly,  in  No.  6,  there 
are  four  axes ;  of  these,  three  are  horizontal,  and 
form  the  diagonals  of  a  regular  hexagon,  as  shown 
by  Fig.  3,  and  one  is  vertical,  and  at  right  angles 


Fig.  3. 


LECT.IX.]          ARGUMENT   FROM   GENERAL   PLAN.  273 

to  the  plane  of  the  first  three.  This  is  called  the 
hexagonal  system.  In  all  these  figures  the  ends  of 
the  axes  have  been  connected  by  lines,  in  order  to 
render  the  character  of  the  systems  more  evident. 

It  is  now  easy  to  see  how  far  the  idea  of  sym- 
metry in  man  corresponds  with  the  idea  in  nature ; 
for,  assuming  these  systems  of  axes  as  they  Formsofthe 
are  found,  we  may  arrange  planes  around  first  system- 
them  in  accordance  with  our  ideas  of  symmetry, 
and  then  compare  the  results  with  nature.  Let  us 
now  take  the  simplest  of  the  systems,  and  fol- 
low out  this  idea.  It  will  be 
evident  on  a  moment's  reflec- 
tion, that  the  number  of  axes 
or  lines  of  symmetry  in  a  crys- 
tal must  be  at  least  three  in 
number,  and  it  will  also  be  evi- 
dent that  the  simplest  arrange- 
ment of  three  straight  lines  is 
that  represented  in  No.  1  of 
Fig.  2.  This  is  called  the  monometric  system  of 
axes,  and  the  lines,  as  stated  above,  are  all  equal, 
and  all  at  right  angles  to  each  other.  Moreover, 
by  passing  a  plane  through  every  two  of  these 
axes,  as  in  Fig.  4,  we  may  divide  the  space  around 
them  into  eight  similar  parts,  called  octants.  Let  us 
proceed  now  to  dispose  planes  symmetrically  around 
these  three  axes,  according  to  our  own  ideas  of  sym- 
metry and  entirely  independent  of  any  observation 
of  nature. 

We  may,  evidently,  begin  by  placing  a  plane  at 


274 


RELIGION   AND    CHEMISTRY. 


[LECT.  IX. 


Fig.  5. 


the  end  of  one  of  the  axes,  and  perpendicular  to  it, 
as  is  represented  in  Fig.  5.  But 
perfect  symmetry  will  now  re- 
quire us  to  place  a  plane  in  a 
similar  position  at  the  other 
end  of  the  same  axis,  and  also 
at  the  two  ends  of  each  of  the 
other  axes.  The  result  of  such 
a  disposition  will  be  a  solid 
bounded  by  six  planes,  called 

a  cube.    No.  2  in  Fig.  12. 

Next  we  may  place  a  plane  so  as  to  touch  the 
ends  of  two  axes  and  to  be  par- 
allel to  the  third,  as  in  Fig.  6. 
But  symmetry  will  now  require 
us  to  place  a  plane  in  every 
other  similar  position,  and  the 
result  of  such  a  disposition  will 
be  a  solid  bounded  by  twelve 
planes,  called  a  dodecahedron. 
No.  3  in  Fig.  12. 

Again,  we  may  place  a  plane  so  as  to  touch  the 
ends  of  all  three  axes,  as  in 
Fig.  7.  Symmetry  will  now 
require  us  to  place  a  plane  in 
every  similar  position,  and  the 
result  will  be  a  solid  bounded 
by  eight  planes,  called  an  octa- 
hedron. No.  1  in  Fig.  12. 

Then  we  may  place  a  plane 
touching  the  end  of  one  axis, 


Fig.  6. 


Fig.  7. 


LECT.IX.]          ARGUMENT   FROM   GENERAL   PLAN. 


275 


but  so   inclined  as  to  intersect  the   prolongation 
of  the  other  two  axes  at  still  greater,  but  equal. 


Fig.  8. 


Fig.  9. 


distances  from  the  centre,  like  the  plane  1:2:2 
in  Fig.  8.*  Symmetry  will  now  require  that  we 
should  place  three  such  planes  in  each  octant,  mak- 
ing twenty-four  planes  in  all,  and  the  intersections 
of  these  planes  will  give  the  form  represented  by 
No.  4  in  Fig.  12. 

Further,  we  may  place  a  plane  touching  the  ends 
of  two  axes,  and  intersecting  the  prolongation  of 
the  third  at  any  given  distance  from  the  centre,  as 
1:1:2  in  Fig.  9.*  Symmetry  will  now  require 
that  we  should  place  three  similar  planes  in  each 
octant,  twenty-four  in  all,  and  the  intersection  of 

*  These  figures  represent  only  one  octant,  see  Fig.  4.  The  portion 
of  the  plane  1  :  2  :  2  in  Fig.  8,  and  of  1  :  1  :  2  in  Fig.  9,  which  appears 
on  the  resulting  form,  has  been  shaded,  as  have  also  the  portions  of  the 
two  planes  which  start  from  the  corresponding  points  on  the  other  axes 
of  the  same  octant.  The  end  of  the  axis  is  assumed  to  be  in  each  case 
at  the  points  marked  1. 


276 


KELIGION   AND    CHEMISTRY. 


[LECT.  IX. 


these  planes  will  give  the  form  represented  by  No. 
5  in  Fig.  12. 


rig.  10. 


Fig.  11. 


Also,  we  may  place  a  plane  touching  the  end  of 
one  axis,  parallel  to  the  second  axis,  and  inter- 
secting the  prolongation  of  the  third  at  some  given 
distance  from  the  centre,  as  either  of  the  planes 
1 :  2  in  Fig.  10.  Symmetry  will  require  us  to  place 
a  plane  in  every  similar  position,  and  we  shall  thus 
obtain  the  figure  bounded  by  twenty-four  faces, 
represented  by  No.  6  in  Fig.  12. 

Lastly,  we  may  place  a  plane  touching  the  end 
of  one  axis,  and  intersecting  the  prolongations  of 
the  other  two  at  unequal  distances  from  the  centre, 
like  either  of  the  two  planes  1  :  3  :  f  in  Fig.  11. 
Symmetry  will  require  us  to  place  six  such  planes 
in  every  octant,  —  two  at  the  end  of  each  axis, — 
making  forty-eight  in  all,  and  we  shall  thus  obtain 
the  form  represented  by  No.  7  in  Fig.  12. 


LECT.  IX.] 


ARGUMENT  FROM   GENERAL  PLAN. 


277 


Fig.  12. 


Of  these  seven  forms,  the  first  three,  which  make 
the  vertices  of  the  triangular  group,  are  absolutely 
invariable.  We  may  have  cubes  of  different  sizes, 
but  the  relative  inclination  of  the  planes  is  abso- 
lutely the  same  in  all,  and  this  is  also  true  of  the 
octahedron,  No.  1,  and  of  the  dodecahedron,  No.  3. 
It  is  different,  however,  with  the  other  four  forms. 
Here  also  the  general  disposition  of  the  planes,  and 
the  general  appearance  of  the  form,  are  always  the 
same  ;  but  the  relative  inclination  of  the  planes  may 
vary  to  a  limited  extent. 

Consider,  for  example,  the  form  No.  5  in  Fig.  12. 
This  form  is  composed  of  planes  touching  the  ends 
of  two  axes  and  intersecting  the  prolongation  of 


278  RELIGION   AND    CHEMISTRY.  [LECT.  IX. 

the  third  at  any  given  distance  from  the  centre,  as 
shown  in  Fig.  9.  Now  it  is  evident  that  we  may 
have  an  infinite  number  of  planes  fulfilling  these 
conditions.  The  plane  must  touch  the  ends  of  two 
axes,  and  so  far  it  is  fixed  ;  but  it  may  intersect  the 
prolongation  of  the  third  at  any  given  distance  from 
the  centre,  —  at  a  distance  of  twice  the  length  of 
the  semi-axis,  or  of  two  and  a  half  times  the  length, 
or  of  three  times  the  length,  or  at  any  other  dis- 
tance. In  this  way  its  position  may  be  varied  infi- 
nitely ;  but  whatever  position  is  given  to  the  first 
plane,  all  the  rest  must  be  perfectly  symmetrical 
with  it. 

Consider,  now,  what  change  such  a  variation  in 
the  position  of  the  planes  will  cause  in  the  form. 
You  will  notice,  by  examining  No.  5  in  Fig.  12,  that 
the  form  may  be  regarded  as  an  octahedron,  No.  1, 
bearing  a  triangular  pyramid  on  each  face.  When 
every  plane  touches  the  ends  of  all  three  axes, 
the  form  becomes  an  octahedron.  If  the  planes, 
still  touching  the  ends  of  two  axes,  intersect  the 
prolongation  of  the  third  at  twice  the  length  of 
the  semi-axis  from  the  centre,  the  form  is  that  rep- 
resented in  No.  5.  If  they  intersect  at  three  times 
this  length,  we  shall  have  a  similar  form,  only  the 
pyramid  will  be  more  elevated.  If  they  intersect 
at  four  times  this  length,  the  pyramid  will  be  still 
higher ;  and  so  on,  until  the  planes  intersect  the 
third  axis  only  at  an  infinite  distance,  in  other 
words  are  parallel  to  it.  Then  the  faces  a  and  b 
on  No.  5  will  fall  into  the  same  plane,  and  we 


LECT.  IX.]          ARGUMENT   FROM   GENERAL  PLAN.  279 

shall  have  the  dodecahedron  No.  3.  Thus  you  see 
that  Fig.  5  is  an  intermediate  form  between  the 
octahedron  No.  1  and  the  dodecahedron  No.  3, 
shading  into  them  on  either  side. 

In  like  manner  No.  4  is  a  variable  form,  interme- 
diate between  the  octahedron  and  the  cube.  So 
also  No.  6  is  a  variable  form,  intermediate  between 
the  dodecahedron  and  the  cube ;  and  finally.  No.  7, 
the  central  form,  is  intermediate  between  all  the 
rest,  as  indicated  by  the  lines  of  the  figure. 

Such  are  the  seven  forms  which  we  have  been 
able  to  obtain  by  arranging  planes  around  the  regu- 
lar system  of  axes,  according  to  our  idea  of  perfect 
symmetry.  Moreover,  since  these  seven  forms,  with 
the  variations  above  described,  are  the  only  forms 
which  we  can  obtain  unless  we  violate  this  idea  of 
perfect  symmetry,  they  may  therefore  be  regarded 
as  the  perfect  embodiments  of  this  idea  as  it  exists 
in  the  human  mind. 

But  it  is  well  known  that  partial  symmetry  is  fre- 
quently as  pleasing  as  perfect  symmetry.  For  ex- 
ample, in  disposing  ornaments  in  a  square  room, 
perfect  symmetry  requires  the  architect  to  place  the 
same  ornament  on  each  of  the  four  walls.  Yet  a 
certain  symmetry  is  preserved,  and  at  the  same 
time  variety  obtained,  if  only  the  ornaments  on  the 
opposite  walls  are  made  alike ;  and  such  a  disposi- 
tion is  less  stiff  than  the  other. 

Now  if  we  apply  this  principle  in  arranging  our 
planes  around  the  axes,  we  shall  obtain  in  addition 
to  the  first  group  of  seven  forms  two  other  and  sim- 


280 


RELIGION   AND    CHEMISTRY. 


[LECT.  IX. 


Fig.  13. 

ilar  groups,  which  may  also  be  regarded  as  the  em- 
bodiment of  the  idea  of  symmetry,  although  not  of 
perfect  symmetry.  These  groups  are  represented 
in  Figs.  13  and  18,  and  the  forms  numbered  alike 
correspond  in  all  three.  The  manner  in  which 
the  forms  of  the  second  group  are  derived  from 
those  of  the  first  is  illustrated  in  Figs.  14,  15, 
16,  and  17. 

Thus  in  Fig.  14  we  have  first  the  shaded  form  of 
the  octahedron  No.  1  of  the  first  group.  Next  we 
have,  circumscribing  the  first,  the  outlines  of  the 
tetrahedron,  as  it  is  called,  which  is  No.  1  of  the  sec- 
ond group,  and  it  will  be  noticed  that  the  planes  of 
the  tetrahedron  correspond  precisely  in  position  to 


LECT.  IX.]          ARGUMENT   FROM   GENERAL   PLAN. 


281 


Fig.  14. 


the  alternate  planes  of  the  octahedron ;  but  they 
are  proportionally  much  larger, 
and  there  are  only  half  as 
many.  To  carry  out  a  previ- 
ous illustration,  it  is  as  if,  in- 
stead of  hanging  a  picture  on 
every  wall  of  a  square  room, 
we  should  hang  one  on  only 
every  other  wall. 

If  now  you  will  turn  back 
to  No.  4  of  the  first  group,  it  will  be  seen  that,  cor- 
responding to  each  plane  of  the 
octahedron,  there  is  in  this  form 
a  set  of  three  planes ;  — just  as 
if,  instead  of  hanging  a  single 
picture  on  each  wall  of  a  square 
room,  we  should  hang  in  each 
place  a  group  of  three  pictures. 
Returning  again  to  No.  4  of  the 
second  group,  it  will  be  evident 
from  inspection,  that  in  this  form  a  set  of  three 
planes  occupies  the  position  of 
each  plane  of  the  tetrahedron, 
—  that  is  to  say,  the  groups  of 
three  pictures  have  been  hung 
on  only  every  other  wall;  and 
if  next  you  examine  Fig.  15  — 
where  the  form  of  the  second 
group  is  circumscribed  around 
the  corresponding  form  of  the 
first  group  —  you  will  readily  perceive  that  the 


Fig.  15. 


Fig.  16. 


282  RELIGION   AND    CHEMISTRY.  [LECT.  IX. 

sets  of  three  planes  on  the  outer  form  occupy  the 
same  position  as  the  alternate  sets  of  three  planes 
on  the  inner  form. 

In  like  manner,  Fig.  16  shows  the  relation  be- 
tween the  two  forms  numbered  5  in  each  group,  and 
Fig.  17,  that  between  the  two  forms  numbered  7. 
In  No.  5  of  the  first  group,  as  in  No.  4,  there  are 
three  planes  in  the  place  of  every  plane  of  the 
octahedron ;  —  that  is,  three  pictures  have  been 
hung  on  each  wall,  but  they  have  been  differently 
arranged  among  themselves.  In  No.  5  of  the  sec- 
ond group  the  relative  arrange- 
ment of  the  three  planes  is  the 
same  as  before,  but  the  sets  are 
placed  only  in  every  other  posi- 
tion, —  that  is,  the  pictures  are 
grouped  in  the  new  way,  but 
hung  only  on  every  other  wall. 
Fi  17  So  also  in  No.  7  of  the  first  group 

we  have  a  set  of  six  planes  in 
the  place  of  every  plane  of  the  octahedron,  —  six 
pictures  peculiarly  grouped  and  hung  on  every  wall. 
In  No.  7  of  the  second  group  we  have  the  same  set 
of  six  planes  placed  only  in  every  other  position,  — 
six  pictures  grouped  as  before  and  hung  on  every 
other  wall. 

The  idea  of  symmetry  which  is  carried  out  in  all 
these  forms  is  evidently  that  of  the  octahedron, 
which  corresponds  to  the  square  room  in  our  illus- 
tration. 

Now  if,  in  developing  this  same  idea,  we  attempt 


LECT.IX.]          ARGUMENT   FROM    GENERAL   PLAN.  283 

to  derive  a  hemihedral  *  from  either  of  the  forms 
No.  2,  3,  or  6  of  the  first  group,  we  shall  be  surprised 
to  find  that  no  new  form  results.  The  reason  is 
this.  If  you  divide  up  the  planes  of  either  of  these 
forms  into  sets  which  shall  correspond  in  position 
to  the  faces  of  the  octahedron,  it  will  be  found  that 
the  same  plane  always  belongs  to  two  or  more  sets. 
It  makes,  therefore,  no  difference  whether  we  place 
the  sets  in  every  position,  or  only  in  every  other 
position.  The  same  form  results  in  both  cases.  It 
is  as  if  the  ornaments  in  our  square  room  were 
brackets,  which  we  could  not  put  in  their  required 
places  in  the  corners  against  one  wall,  without  hav- 
ing them  touch  the  adjoining  wall  also. 

Thus  it  is  that  these  three  forms,  regarded  from 
one  point  of  view,  are  hdohedralft  and  belong  to  the 
first  group,  while,  regarded  from  another,  they  are 
hemihedral,*  and  belong  to  the  second.  Such  anoma- 
lies as  these  are  not  uncommon  in  science.  It  is 
frequently  the  case  that,  to  our  finite  minds  at  least, 
the  same  substance,  or  the  same  form,  is  an  embod- 
iment of  two  different  ideas,  so  that,  while,  regarded 
from  one  point  of  view,  it  falls  into  one  group  of  our 
classification,  regarded  from  another,  it  belongs  to 
quite  a  different  one. 

Passing  lastly  to  the  third  group,  Fig.  18,  we  find 
another  set  of  hemihedral  forms,  but  they  are  based 
on  quite  a  different  idea  of  symmetry ;  not  the  idea 
embodied  in  the  octahedron,  but  that  which  is  real- 

*  Having  half  the  number  of  possible  planes, 
f  Having  the  full  number  of  possible  planes. 


284 


RELIGION   AND    CHEMISTRY. 


[LECT.  IX. 


Fig.  18. 

ized  in  the  form  No.  6  of  Fig.  12,  called  the  tetra- 
kis-hexahedron  (from  Greek  words  meaning  four 
times  six  planes).  This  form  is  bounded  by  twenty- 
four  planes  placed  in  the  positions  already  indicated 
in  Fig.  10.  If  now  we  place  planes  only  in  every 
other  one  of  these  twenty-four  positions  —  as  shown 
in  Fig.  19' —  we  shall  obtain  the  form  No.  6  of  Fig. 
18,  bounded  by  twelve  pentagons. 

Comparing  next  No.  7  of  Fig.  12  with  No.  6  of 
the  same  group,  we  shall  find  that  a  pair  of  planes  in 
the  first  corresponds  to  each  single  plane  in  the  last. 
When,  therefore,  we  place  a  pair  of  planes  in  every 
one  of  the  twenty-four  positions  occupied  by  the 
planes  of  No.  6,  we  get  the  form  No.  7,  bounded  by  its 


LKCT.  IX.] 


ARGUMENT  FROM  GENERAL  PLAN. 


285 


Fig.  19. 


forty-eight  planes ;  but  if  we  place  a  pair  of  planes 
only  in  every  other  position,  as  shown  by  Fig.  20, 
we  shall  develop  the  form  represented  by  No.  7 
of  Fig.  18,  which  is  bounded  by  only  twenty-four 
planes.  Applying  now  the  same  idea  to  the  other 
five  forms  of  the  first  group,  we 
find  that  no  new  forms  are  pro- 
duced; so  that  of  the  forms  of 
the  third  group  only  two  differ 
from  those  of  the  first,  and  the 
reason  here  is  the  same  as  that 
already  given  to  explain  the  sim- 
ilar cases  in  the  second  group.  The 
like  forms  may  be  regarded  as 
embodying  at  the  same  time  two  different  ideas  of 
symmetry. 

I  could  easily  show  that  the  hemihedral  forms  in 
each  of  the  last  two  groups  are  related  among  them- 
selves precisely  in  the  same  way  as  are  the  holohedral 
forms  of  the  first  group,  but  I 
am  afraid  I  have  already  been 
too  abstruse,  and  I  will  not  fur- 
ther trespass  on  your  patience. 
Suffice  it  then  to  say,  that  the 
three  groups  of  forms  we  have 
figured  are  the  only  forms 
which  we  can  obtain  by  ar- 
ranging planes  around  the  monometric  system  of 
axes,  according  to  the  idea  of  symmetry  as  it  exists 
in  our  minds,  and  they  may  therefore  be  regarded 
as  the  complete  embodiment  of  that  idea. 


Fig.  20. 


286  KELIGION   AND    CHEMISTRY.  [LECT.  IX. 

Let  us  now  turn  to  Nature,  and  compare  her 
handiwork  with  these  products  of  our  own  thought. 
Mineralogists  have  found  that  the  crystals  of  gold, 
silver,  copper,  the  diamond,  the  ruby,  common  salt, 
alum,  fluor-spar,  galena,  iron  pyrites,  and  a  very 
large  number  of  other  substances,  are  all  formed 
around  the  monometric  system  of  axes,  and  these 
crystals  have  invariably*  one  or  the  other  of  the 
forms  we  have  described.  Moreover,  the  forms  of 
the  crystals  of  each  substance  are  limited  to  those  of 
one  group.f  Thus  we  find  crystals  of  fluor-spar  in  all 
the  forms  of  the  first  group,  but  never  in  those  which 
are  peculiar  to  the  other  two.  In  like  manner,  the 
crystals  of  a  complex  ore  of  copper,  called  tetra- 
hedrite,  have  exclusively  the  forms  of  the  second 
group,  while  those  of  iron  pyrites  occur  only  in  the 
forms  of  the  third.  Each  substance  follows  a  cer- 
tain idea  of  symmetry,  which  seems  to  be  inherent 
and  a  part  of  its  very  nature  ;  so  much  so,  that 
when  from  any  cause  the  character  of  the  symmetry 
changes,  the  substance  loses  its  identity,  and  even  if 
its  chemical  composition  does  not  change,  it  becomes 
to  all  intents  and  purposes  a  different  substance. 

What  has  been  shown  to  be  true  of  the  regular 
system  of  axes  is  equally  true  of  the  five  other  sys- 
tems which  have  been  observed  in  nature.  By  ar- 
ranging planes  symmetrically  around  these  axes  we 

*  In  some  cases  a  substance  crystallizes  in  the  forms  of  two  different 
systems,  but  then  the  properties  differ  in  the  two  states  as  widely  as  the 
form.  The  diamond  and  plumbago  are  examples  of  this. 

f  There  may  be  exceptions  to  this  rule,  but  if  so  they  have  not  been 
distinctly  stated. 


LECT.IX.]          ARGUMENT   FROM   GENERAL   PLAN.  287 

can  develop  an  immense  number  of  forms  by  a 
pure  process  of  thought,  and  it  is  these  forms  alone 
which  we  find  among  natural  crystals.  The  pro- 
ducts of  Nature's  laboratory  correspond,  then,  ex- 
actly to  the  results  of  our  own  thoughts ;  and  how 
can  we  resist  the  conclusion  that  they  are  the  mani- 
festations of  the  thoughts  of  an  intelligent  Creator  ? 
In  the  language  of  science,  the  crystal  is  said  to 
obey  the  law  of  symmetry ;  but  obviously  this  law 
is  merely  the  reflection  of  the  same  simple  idea 
which  exists  in  our  own  minds,  and  which  must 
have  previously  existed  in  the  mind  of  God.  The 
whole  science  of  crystallography  is  a  development 
of  this  idea  of  symmetry.  Like  geometry,  it  is  a 
product  of  pure  thought,  and  its  truths  are  entirely 
independent  of  their  material  forms.  Indeed,  the 
mineral  kingdom,  so  far  as  it  is  known,  does  not 
perfectly  represent  the  idea  of  symmetry,  even  as 
it  exists  in  the  human  mind.  There  are  possible 
forms  which  have  never  been  obtained  in  nature, 
and  the  science,  even  as  we  know  it,  could  never 
have  been  developed  by  observation  alone. 

By  following  out  the  simple  idea  of  symmetry, 
which  is  common  to  all  men,  we  have  found  that  the 
results  of  our  own  thought  perfectly  agree  Idea  of 
with  the  facts  of  nature.    Let  us  now  take  number- 
another  of  the   primary  ideas  which  exist  in  the 
human  mind,  and  see  how  fully  that  is  realized  in 
the  material  creation.     The  idea  of  number  is  as  in- 
herent in  the  mind  as  that  of  symmetry.     I  shall 
not  attempt  to  discuss  its  origin  or  trace  its  devel- 

19 


288  RELIGION  AND    CHEMISTRY.  [LECT.  IX 

opment ;  but  assuming,  as  all  will  admit,  that  the 
results  of  human  skill  constantly  exhibit  simple  nu- 
merical relations,  let  us  inquire  whether  the  same 
characteristic  may  not  be  discovered  in  nature. 

I  have  already  defined  a  chemical  element  as  a 
substance  which  has  never  as  yet  been  decomposed, 
chemical  an^  all  the  matter  with  which  man  is  ac- 
equivaients.  quainted  is  composed  of  one  or  more  of 
sixty-two  elementary  substances.  When  two  of 
these  elements  unite  together  to  form  a  compound 
body,  the  proportions  in  which  they  combine  are 
not  decided  by  chance.  You  cannot  unite  these 
elementary  substances  in  any  proportion  you  please. 
The  proportion  in  each  case  is  determined  by  an 
unvarying  law,  and  the  amounts  required  of  either 
substance  are  weighed  out  by  Nature  in  her  delicate 
scales  with  a  nicety  which  no  art  can  attain.  Thus, 
for  example,  23  ounces  of  sodium  will  exactly  unite 
with  35.5  ounces  of  chlorine;  and  if  you  use  precisely 
these  proportions  of  the  two  elements,  the  whole  of 
each  will  disappear  and  become  merged  in  the  com- 
pound, which  is  our  common  table  salt.  But  if,  in 
attempting  to  make  salt,  we  bring  together  clumsily 
23.5  ounces  of  sodium  and  35.5  ounces  of  chlorine, 
Nature  will  simply  put  the  extra  half-ounce  of  so- 
dium on  one  side,  and  the  rest  will  unite. 

The  numbers  in  the  table  on  page  290  give  the 
proportions  by  weight  in  which  the  elements  unite. 
For  example,  eight  pounds  of  oxygen  combine  with 
six  pounds  of  carbon,  with  fourteen  pounds  of  nitro- 
gen, and  so  with  the  numbers  given  for  the  other 


LECT.IX.]          ARGUMENT   FROM   GENERAL   PLAN.  289 

substances.  We  call  these  numbers  combining  pro- 
portions, and  sometimes  chemical  equivalents,  be- 
cause in  many  cases  they  represent  equivalent 
quantities  of  the  respective  elements.  Thus,  if  we 
remove  sulphur  from  a  chemical  compound,  and  fill 
its  place  with  oxygen,  it  is  found  that  for  every  six- 
teen ounces  of  sulphur  removed  we  must  supply 
eight  ounces  of  oxygen.  Hence,  in  a  chemical 
sense,  eight  ounces  of  oxygen  are  the  equivalent  of 
sixteen  ounces  of  sulphur ;  but  the  same  is  not 
necessarily  true  of  all  the  elements. 

The  standard  of  these  weights  is  of  course  arbi- 
trary, but  if  one  number  stands  for  pounds,  all  the 
rest  stand  for  pounds,  or  if  one  stands  for  ounces,  all 
the  rest  stand  for  ounces.  It  is  usual,  however,  to 
leave  the  standard  indefinite,  and  speak  of  so  many 
parts.  Again,  the  weights  have  only  relative  val- 
ues ;  but  if  we  give  to  any  one  a  definite  value,  all 
the  rest  assume  definite  values.  Our  unit  must  ne- 
cessarily be  more  or  less  arbitrary.  Most  chemists 
take  hydrogen  for  the  unit  of  weight,  and  the  num- 
bers given  in  the  table  express  the  equivalent 
weights  of  the  other  elements  calculated  on  this  as- 
sumption. But  we  might  take  any  one  of  the  ele- 
ments as  our  starting-point,  and  many  of  the  Euro- 
pean chemists  use  a  system  of  equivalents  calculated 
on  the  assumption  that  the  equivalent  of  oxygen  is 
100.  This  assumption  gives  an  entirely  different 
system  of  numbers ;  but  the  difference  is  of  no  im- 
portance so  long  as  the  relative  values  remain  un- 
changed. 


290 


RELIGION   AND    CHEMISTRY. 


[LECT.  IX. 


I 


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LECT.IX.]          ARGUMENT   FROM   GENERAL   PLAN. 


291 


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292  RELIGION   AND    CHEMISTRY.  [LECT.  IX. 

Dr.  Prout  was  the  first  to  notice  that  many  of 

the    chemical    equivalents    were   simple    multiples 

of  the   equivalent   of  hydrogen,  and   he 

Many  of  the  .  J 

equivalents  are  thought  that,  if  this  equivalent  were  taken 

whole  numbers.  .  equivalentg 


be  expressed  by  whole  numbers.  The  progress  of 
chemistry  has  not  tended  to  confirm  this  view,  but 
on  examining  the  table  it  will  be  noticed  that  a 
large  number,  at  least,  of  the  chemical  equivalents 
on  the  hydrogen  scale  are  whole  numbers,  and  this 
is  especially  true  of  those  elements  which  have  al- 
ready been  mentioned  as  forming  almost  the  whole 
of  the  earth's  crust.  Thus  we  find  in  these  elemen- 
tary forms  of  matter  —  the  blocks  with  which  the 
universe  has  been  built  —  the  same  simple  numeri- 
cal relations  which  everywhere  appear  in  the  con- 
structions of  man. 

Still  simpler  numerical  relations  will  be  discovered 
if  we  consider  the  different  compounds  formed  by 
Law  of  multiple  the  same  elements.  The  proportions  of 
proportions.  fae  elements  which  enter  into  such  com- 
pounds always  bear  a  very  simple  numerical  relation 
to  each  other.  Thus  there  are  five  compounds  of 
oxygen  and  nitrogen  which  contain  these  elements 
in  the  proportions  indicated  in  the  following  table. 

Compounds  of  Oxygen  and  Nitrogen. 

Nitrogen.  Oxygen. 

Protoxide  of  Nitrogen  14  parts.  8  parts. 

Deutoxide  of  Nitrogen  14     "      8X2  =  16     " 

Nitrous  Acid  14     «      8  X  3  =  24     « 

Hyponitric  Acid  14     "      8  X  4  =  32     « 

Nitric  Acid  14     "      8  X  5  =  40     " 


LECT.IX.]          ARGUMENT   FROM   GENERAL   PLAN.  293 

It  will  be  noticed  that  the  proportions  of  oxygen 
in  these  compounds  are  in  all  cases  simple  multiples 
of  eight,  the  proportion  in  the  first.  In  like  man- 
ner, the  compounds  of  manganese  with  oxygen 
show  similar  relations. 

Compounds  of  Oxygen  and  Manganese. 

Manganese.  Oxygen. 

Protoxide  of  Manganese  27.5  parts.  8  parts. 

Sesquioxide  of  Manganese  27.5     «      8  X  1£  =  12     " 

Hyperoxide  of  Manganese  27.5     "      8X2=16     " 

Manganic  Acid  27.5     "      8  X  3    =  24     « 

Permanganic  Acid  27.5     "      8  X  3£  =  28     " 

The  relation  is  not  quite  so  simple  as  in  the  other 
case,  but  still  the  same  general  truth  is  evident,  and 
these  two  examples  are  fair  illustrations  of  what 
has  been  observed  throughout  the  whole  range  of 
chemical  compounds. 

A  large  number  of  the  chemical  elements  are 
either  found  naturally  in  the  aeriform  condition,  or 
else  can  be  converted  into  gases  by  a 

J  Combining 

moderately  high  temperature,  and  some  proportions  by 
remarkably  simple  numerical  relations  will 
appear  if  we  consider  the  proportions  in  which 
these  gases  combine  by  volume.  We  gave  above 
a  table  of  combining  proportions  by  weight,  and 
we  give  on  the  next  page  a  table  of  combining  pro- 
portions by  volume. 

What  could  be  simpler  than  the  numerical 
relations  presented  by  this  table?  These  gases 
combine  either  in  the  proportion  of  one  volume 


294 


KELIGION   AND    CHEMISTRY. 


[LECT.  IX. 


Name  of  Gas. 

Arsenic 

Brominic 

Chlorine 

Cyanogen 

Fluorine 

Hydrogen 

Iodine 

Mercury 

Nitrogen 

Oxygen 

Phosphorus 

Selenium 

Sulphur 


Combining  Proportions 

by  Volume. 

Volume. 

Sp.  Gr. 
Calculated.* 

1 

10.365 

2 

5.526 

2 

2.450 

2 

1.797 

2 

1.301 

2 

0.069 

2 

8.768 

2 

6.976 

2 

0.968 

1 

1.106 

1 

4.334 

1 

4.406 

1 

2.211 

Sp.  Gr. 
Observed. 

10.65 
5.54 
2.47 
1.81 

0.069 

8.716 

6.976 

0.971 

1.106 

4.42 

5.68 

2.23 


(that  is,  one  quart,  one  pint,  one  cubic  foot,  or 
whatsoever  unit  of  volume  we  employ)  of  one  gas, 
to  one  of  the  other,  or  else  one  volume  of  one  to 
two  of  the  other.  It  is  true,  however,  that  combi- 
nation may  take  place  in  any  simple  multiples  of 
these  proportions,  as  in  the  case  of  the  equivalents 
by  weight.  For  example,  the  five  compounds  of 
oxygen  and  nitrogen  contain  respectively,  — 


Protoxide  of  Nitrogen 
Deutoxide  of  Nitrogen 
Nitrous  Acid 
Hyponitric  Acid 
Nitric  Acid 


*  These  specific  gravities  are  calculated  on  the  assumption  that  the 
combining  proportions  by  volume  are  exact.  It  will  be  noticed  that 
they  very  closely  agree  with  the  observed  specific  gravities  given  in  the 
last  column. 


Oxygen. 

2  volumes. 

Nitrogen. 

1  volume. 

2 

a 

2 

a 

2 

a 

3 

u 

2 

u 

4 

u 

2 

it 

5 

u 

LECT.  IX.]          ARGUMENT   FROM   GENERAL   PLAN.  295 

But  there  are  numerical  relations  between  the 
chemical  elements  even  more  remarkable  than  those 
we  have  studied.  These  substances,  which  classification 
we  call  elements  solely  because  they  have  ofelements- 
never  been  decomposed,  vary  very  greatly  in  their 
properties.  At  the  ordinary  temperature  of  the 
air,  some  are  gases,  some  are  liquids,  and  some  are 
solids.  Some  are  highly  corrosive,  like  chlorine, 
and  others  perfectly  inert,  like  nitrogen.  Some 
have  a  bright  metallic  lustre,  like  gold  or  silver, 
and  others  are  dull,  like  charcoal  or  sulphur.  In- 
deed, we  find  among  these  substances  almost  every 
possible  variety  of  qualities. 

These  elements  are  not  to  be  regarded,  however, 
as  so  many  distinct  creations,  each  endowed  with 
the  peculiar  properties  which  fit  it  for  the  uses  it 
subserves  in  the  universe,  but  each  entirely  inde- 
pendent of  all  the  rest.  On  the  contrary,  the  whole 
world  of  matter  is  but  one  creative  thought,  ex- 
pressed with  various  modifications  in  the  different 
elements,  but  yet  one  thought  comprehending  all. 
It  is .  true  that  we  have  not  obtained  more  than 
the  most  distant  glimpses  of  this  Divine  plan,  but 
still  we  have  seen  enough  to  convince  us  that 
there  is  such  a  plan  underlying  the  whole  material 
creation. 

Of  the  sixty-four  substances  which  have  never 
been  decomposed,  and  which  are  therefore  regarded 
as  elements,  a  large  number  are  so  exceedingly  rare 
and  so  difficult  to  obtain  that  their  properties  have 
not  been  fully  studied,  and  their  relations  to  one 


296  RELIGION   AND    CHEMISTRY.  [LECT.  IX. 

another  are  not  yet  known.  Disregarding  those 
italicized  in  the  table  on  page  290,  the  remaining 
elements  may  be  classified  in  six  families  or  series, 
three  of  which  are  given  on  the  opposite  page  of  the 
same  table.  We  shall  best  be  able  to  understand 
the  principles  of  the  classification  by  examining  in 
detail  one  of  the  families  of  elements.  We  might 
take  either  of  the  six,  and  I  have  selected  the  Nine 
Series  only  because  the  members  of  this  family  of 
elements  are  probably  more  familiar  to  you  than 
any  others.  The  elements  which  compose  the  nine 
series  are  all  highly  active  and  corrosive  chemical 
agents.  They  all  form  analogous  compounds.  They 
all  have,  so  far  as  is  known,  the  same  crystalline 
form,  and  may  replace  one  another  in  a  chemical 
compound  without  changing  the  form  of  the  sub- 
stance. Moreover,  they  resemble  one  another  in 
many  other  properties  which  we  have  not  time  to 
discuss  in  this  connection. 

If  the  resemblances  are  great,  however,  the  differ- 
ences are  great  also ;  but  then  these  differences  fol- 
Lawof  low  a  simple  and  well-established  law  of 
progression,  progression.  The  properties  of  this  fam- 
ily of  elements  vary,  as  we  descend  the  series,  by 
regular  steps.  Let  me  illustrate.  Consider  first 
the  physical  condition  of  these  substances.  Ozone 
is  the  active  modification  of  oxygen,  and  so  persist- 
ently does  it  retain  its  aeriform  condition  that  no 
amount  of  mechanical  pressure  and  cold  which  we 
can  command  is  sufficient  to  reduce  it  to  a  liquid. 
The  next  element,  fluorine,  is  also  a  gas,  but  it  is  so 


LECT.  IX.]          ARGUMENT   FROM   GENERAL   PLAN.  297 

highly  corrosive  that  we  have  not  yet  been  able  to 
experiment  upon  it.  Cyanogen  is  a  very  remark- 
able substance.  It  is  really  a  compound,  but  its 
properties  resemble  so  closely  those  of  the  other 
elements  of  the  series  that  I  have  classified  it  with 
them.  It  is  a  gas  which  can  by  great  pressure  and 
cold  be  changed  to  a  liquid.  Chlorine,  although 
generally  known  as  a  gas,  can  be  liquefied  still  more 
readily.  Bromine  is  a  very  volatile  liquid,  which, 
at  the  temperature  of  145°  Fahrenheit,  becomes  a 
gas.  Iodine,  finally,  is  a  solid,  but  a  solid  which  is 
very  fusible,  and  becomes  a  gas  at  a  temperature  of 
347°.  At  the  temperature  of  a  common  bread-oven, 
all  these  substances  would  be  gases,  and,  as  is  shown 
in  the  eighth  column  of  the  table,  the  densities  of 
these  gases  gradually  increase  as  you  descend  in  the 
series.  Pass  now  to  the  color  of  these  elements 
wrhen  in  the  state  of  gas,  and  you  will  find  that  there 
is  a  beautiful  chromatic  gradation  between  them. 
Ozone  is  colorless ;  chlorine  is  yellow,  inclining  to 
green  ;  bromine,  orange-red  \  and  iodine,  violet. 
Consider  next  the  equivalents  of  these  elements,  and 
you  will  discover  that  they  stand  in  a  very  simple 
relation  to  each  other.  The  equivalent  of  ozone  is 
8  ;  that  of  fluorine  is  approximately  8  -j-  9  =  17 ; 
that  of  cyanogen,  17  -j-  9  =  26  ;  that  of  chlorine, 
26  -f-  9  =  35.  It  is  probable  that,  if  the  series 
were  complete,  the  equivalent  of  the  next  element 
to  chlorine  would  be  35  -[-  9  =  44,  and  those  of 
the  three  succeeding  elements,  53,  62,  and  71  re- 
spectively ;  but  no  such  elements  are  known.  The 


298  RELIGION   AND    CHEMISTRY.  [LECT.  IX. 

next  step,  however,  gives  us  eighty,  which  is  the 
equivalent  of  bromine.  Then  again  there  are  four 
steps  not  represented,  but  at  the  fifth  step  we  come 
to  iodine,  whose  equivalent  is  125.  You  notice  that 
the  common  difference  of  these  numbers  is  in  every 
case  nine,  and  for  this  reason  I  have  named  this 
family  of  elements  the  Nine  Series. 

A'  relationship  like  that  I  have  just  described, 
exists  among  the  members  of  the  other  five  fami- 
lies into  which  I  have  classified  the  chemical  ele- 
ments. The  properties  of  the  elementary  sub- 
stances in  each  family  vary  according  to  a  similar 
law  of  progression ;  but  the  number  which  ex- 
presses the  common  difference  of  the  equivalents 
is  different  for  each  series,  and  characterizes  the 
family.  The  numbers  besides  9  are  8,  6,  5,  4,  and 
3,  respectively,  and  in  each  case  I  have  given  to 
the  series  the  name  of  the  numeral  which  distin- 
guishes it. 

How  evidently,  then,  the  properties  of  the  ele- 
ments conform  to  the  idea  of  number !  It  is  true 
that  our  classification  is  at  fault  in  many  particu- 
lars, and  I  do  not  suppose  that  the  order  of  pro- 
gression here  given  is  more  than  a  very  distant 
approximation  to  the  actual  law  of  nature ;  but  the 
fact  that  some  such  law  exists,  and  that  it  is  based 
on  simple  numerical  relations,  I  believe  is  beyond  a 
doubt.  The  same  principle  of  classification  applies 
to  compound  bodies  as  well  as  to  elements,  and  I 
confidently  look  forward  to  the  time  when  it  will 
be  possible  to  classify  all  substances  in  one  compre- 


LECT.IX.]    ARGUMENT  FROM  GENERAL  PLAN.        299 

hensive  scheme,  and  to  represent  the  relations  of 
their  properties  by  simple  arithmetical  formulae. 

Similar  numerical  relations  are  found  throughout 
the  whole  universe  of  matter.     In  the  solar  system, 
for  example,  with  the  exception  of  Nep-  intervaig 
tune,  the  intervals  between  the  orbit   of  betweenthe 

orbits  of  the 

Mercury  and  the  orbits  of  the  other  plan-  planets. 
ets  go  on  doubling,  or  nearly  so,  as  we  recede  from 
the  Sun.  Thus  the  interval  between  the  Earth  and 
Mercury  is  nearly  twice  as  great  as  that  between 
Venus  and  Mercury,  the  interval  between  Mars 
and  Mercury  nearly  twice  as  great  as  that  between 
the  Earth  and  Mercury,  and  so  on.  Again,  if  we 
compare  the  periods  of  revolution  around  the  Sun, 
expressed  in  days,  we  shall  find  another  simple 
numerical  relation,  as  shown  by  the  following  table. 

Law  of  Periodic  Times. 

Observed.  Theoretical.  Fractions. 


I 
f 

A 


Neptune 

60,129 

62,000 

Uranus 

30,687 

31,000 

Saturn 

10,759 

10,333 

Jupiter 

4,333 

4,133 

Asteroids 

1,200  to  2,000 

1,550 

Mars 

687 

596 

Earth 

365 

366 

Venus 

225 

227 

Mercury 

88 

87 

It  will  be  noticed  that  the  period  of  Uranus  is  \ 
that  of  Neptune,  the  period  of  Saturn  \  that  of 
Uranus,  the  period  of  Jupiter  about  f  that  of 


300  RELIGION   AND    CHEMISTRY.  [LECT.  IX. 

Saturn,  the  period    of  the  Asteroids  about  f  that 
of  Jupiter,  the  period  of  Mars  about  T5T 

Ratios  between  r  . 

the  periods  of    that  of  the  Asteroids,  the  period  of  V  enus 

the  planets. 


Mercury  about  j-f  that  of  Yenus.  The  successive 
fractions  are  very  simply  related  to  each  other,  as 
will  at  once  appear  on  writing  them  in  a  series, 

i,  i>  t>  i  T53,  A>  ii  &c. 

Notice  that,  after  the  first  two,  each  succeeding  frac- 
tion is  obtained  by  adding  together  the  numerators 
of  the  two  preceding  fractions  for  a  new  numera- 
tor, and  the  denominators  for  a  new  denominator. 
From  this  series,  however,  the  Earth  is  excluded. 
Its  time  of  revolution  is  almost  exactly  T8^  of  that 
of  Mars,  and  that  of  Venus  nearly  ||  of  that  of  the 
Earth  ;  but  although  these  fractions  do  not  fall  into 
the  above  series,  they  are  members  of  a  comple- 
mentary series  beginning 

i>  f  >  f  >  fc  T83>  if,  &c. 

This  simple  relation  was  discovered  by  Professor 
Peirce,  and  he  has  proposed  an  explanation  for  the 
anomaly  presented  by  the  Earth.  But  it  is  not 
important  to  dwell  on  this  point.  Our  only  object 
was  to  show  that  simple  numerical  relations  appear 
in  the  planetary  system,  and  this,  as  I  trust,  has 
been  fully  illustrated. 

Passing  now  to  the  vegetable  kingdom,  we  find 
again  the  same  numerical  laws.  The  leaves  of 
Arrangement  a  plant  are  always  arranged  in  spirals 
of  leaves.  around  the  stem.  If  we  start  from  any 


LECT.  IX.] 


ARGUMENT  FROM   GENERAL   PLAN. 


301 


one  leaf,  and  count  the  number  of  leaves  around 
the  stalk  and  the  number  of  turns  of  the  spiral  until 
we  come  to  a  second  leaf  immediately  over  the 
first,  we  find  that  for  any  given  plant,  as  an  apple- 
tree  for  example  (see  Figs.  21  and  22*),  the  number 


H 


Fig.  21. 


Fig.  22. 


of  leaves  and  the  number  of  turns  of  the  spiral  are 
always  absolutely  the  same.  The  simplest  arrange- 
ment is  where  the  coincidence  occurs  at  the  second 
leaf,  after  a  single  turn  of  the  spiral ;  and  this  may 
be  expressed  by  the  fraction  ^,  whose  numerator  de- 
notes the  number  of  turns  of  the  spiral,  and  whose 
denominator  the  number  of  leaves.  The  next  sim- 
plest arrangement  is  when  the  coincidence  occurs  at 
the  third  leaf,  after  a  single  turn  of  the  spiral,  and 
may  be  expressed  by  the  fraction  J.  These  two 
fractions  express  respectively  the  greatest  and  the 
smallest  divergence  between  two  successive  leaves 
which  has  been  observed.  The  angle  between  two 

*  These  figures  are  from  Gray's  Botanical  Text-Book. 


302 


RELIGION   AND    CHEMISTRY. 


[LECT.  IX. 


successive  leaves,  therefore,  is  never  greater  than 
ISO0,  or  half  the  circumference  of  the  stem,  and 
never  less  than  120°,  or  one  third  of  the  circumfer- 
The  arrangement  next  in  simplicity  is  where 


ence. 


the  coincidence  occurs  at  the  fifth  leaf,  after  two 
turns  of  the  spiral,  as  is  represented  in  the  preced- 
ing figures.  Other  examples  are  given  in  the  table 

LAW  OF  PHYLLOTAXIS  (Leaf- Arrangement). 


Name  of  Plant. 

Number 
of  Turns 
of  Spiral.* 

Number 

of  Leaves.* 

Fraction. 

Angle  of  Divergence, 
between  two 
successive  Leaves. 

Grasses, 

1 

2 

i 

180° 

Sedges, 

1 

3 

120° 

Cherry,  I 

2 

5 

| 

144° 

Poplar,  ) 

Holly,    '       ) 
Callistemon,  > 

3 

8 

I 

135° 

Aconite,        ) 

Eosettes  of  the  1 

Houseleek, 
Cones  of  the       f 

5 

13 

A 

138°  28' 

White  Pine,     J 

x 

Cones  of  the  Euro-  ) 
pean  Larch,         ) 

8 

21 

& 

137°  9' 

Certain  Pine  Cones, 

13 

34 

if 

137°  39' 

Certain  Pine  Cones, 

21 

55 

n 

137°  27' 

Typical  arrangement  which  would  expose  to  the  ) 
Sun's  rays  the  greatest  leaf-surface,                           ) 

137°  30'  28" 

which  follows,  and  it  will  be  seen  that  we  have  pre- 
cisely the  same  series  of  fractions  in  the  arrange- 
ment of  leaves  around  the  stem  of  a  plant  which 
appears  in  the  periods  of  the  planets.  The  fractions 
of  this  series  are  all  gradual  approximations  to  a 

*  Before  a  leaf  occurs  vertically  over  the  first. 


LECT.IX.]          ARGUMENT  FROM   GENERAL  PLAN.  303 

mean  fraction  between  J  and  £,  which  would  give 
the  most  nearly  uniform  distribution  possible  to  the 
leaves,  and  expose  the  greatest  surface  to  the  sun. 

But  this  law  does  not  stop  with  the  plants.  The 
same  series  of  fractions  expresses  also  the  spiral  ar- 
rangement of  the  tentacles  of  the  Polyp  and  of  the 
spines  of  the  Echinus.  Thus  through  the  whole 
realm  of  nature,  from  the  structure  of  the  crystals 
to  the  dimensions  of  the  human  form,  a  similar  nu- 
merical simplicity  is  preserved. 

Have  you  never  recognized  the  composition  of 
your  friend  in  some  anonymous  literary  article,  by 
a  peculiar  phraseology,  a  turn  of  style,  or  a  method 
of  thought  which  no  artifice  can  conceal  ?  Have 
you  never  felt  a  glow  of  pleasure  when  you  unex- 
pectedly discovered  on  the  walls  of  a  picture-gal- 
lery the  work  of  a  well-known  artist,  marked  by 
some  peculiarity  of  grouping  or  coloring  ?  Has 
your  attention  never  been  quickened  when  an  or- 
chestra has  suddenly  struck  into  a  new  theme  of  a 
favorite  composer,  never  heard  before,  but  unques- 
tionably his  ?  If  you  have  experienced  these  or 
similar  emotions,  you  know  something  of  the  force 
with  which  such  numerical  laws  impress  the  mind 
of  the  student  of  nature,  and  you  also  know  how 
difficult  it  is  to  make  the  power  of  such  impressions 
understood.  I  wish  I  could  give  you  a  full  concep- 
tion of  this  power ;  for  you  cannot  otherwise  feel  the 
full  force  of  the  evidence  which  these  facts  afford. 
They  point  directly  to  an  intelligence  in  nature  Iike4 
our  own,  and  they  are  a  seal  to  the  declaration  of 

20 


304  RELIGION  AND   CHEMISTRY.  [LECT.  IX. 

the  Bible,  that  man  was  created  in  the  image  of  his 
God. 

The  broken  porticos  of  the  Parthenon  still  stand 
on  the  Acropolis  at  Athens  to  excite  the  imitation 
and  win  the  admiration  of  the  architect.  That 
beauty  of  outline  and  those  faultless  proportions, 
which  modern  art  has  copied,  but  never  excelled, 
all  depend  on  an  exact  conformity  of  all  the  parts 
to  the  laws  of  symmetry  and  to  simple  numerical 
ratios.  We  justly  regard  that  ruined  temple  as  the 
evidence  of  the  highest  intelligence ;  and  when  we 
find  the  same  symmetry,  the  same  numerical  ratios, 
appearing  everywhere  in  nature,  how  can  we  refuse 
to  admit  that  they  also  are  the  evidence  of  intelli- 
gence and  thought  ?  Moreover,  since  the  laws  of 
symmetry  and  number  pervade  the  whole  universe, 
from  the  structure  of  the  solar  system  down  to  the 
organization  of  a  worm,  they  prove,  if  they  prove 
anything,  that  the  whole  is  the  manifestation  of 
the  thoughts  of  the  one  great  Jehovah,  who  in 
the  beginning  created  all  things  by  the  word  of 
His  power. 


LECTUEE     X. 

ARGUMENT  FEOM  GENERAL  PLAN  (CONCLUDED).— NECESSARY  LIM- 
ITATIONS OF  SCIENTIFIC  AND  RELIGIOUS  THOUGHT. 

IN  my  last  Lecture  I  endeavored  to  show  that 
the  laws  of  nature,  so  far  from  proving  that  the 
world  is  governed  by  an  inexorable  neces-  The  error  Of 
sity,  furnish  the  strongest  evidence  of  an  Pantheism- 
overruling  mind.  We  must  be  careful,  however, 
not  to  misinterpret  this  evidence ;  for  analogies 
like  those  we  have  studied  led  Schelling  and  the 
philosophers  of  his  school  to  regard  outward  nature 
not  merely  as  the  result  of  the  Divine  Thought,  but 
as  identical  with  that  thought,  and  inseparable  from 
it.  Indeed,  there  are  many  among  us  who  regard 
the  material  universe  as  the  manifestation  of  God, 
in  the  same  intimate  sense  in  which  our  bodies  are 
the  manifestation  of  our  own  personality ;  who 
therefore  believe  that  the  world  is  and  always  has 
been  a  part  of  His  Eternal  Being,  and  who  look 
upon  the  laws  of  nature  not  merely  as  the  mani- 
festation of  an  Infinite  Intelligence,  but  as  a  part 
of  that  Intelligence  itself. 

This  philosophy  may  be  made  to  appear  very 
attractive,  and  even  very  reverential ;  but  when 
followed  out  to  its  logical  consequences,  it  reduces 
God  to  the  level  of  nature,  and  merges  His  being 
in  the  matter  He  created.  We  must  be  as  careful 


306  KELIGION   AND    CHEMISTRY.  [LECT.  X. 

to  avoid  the  snares  of  pantheism,  as  the  slough  of 
materialism.  Both  are  equally  destructive  of  true 
religion,  and,  although  they  lie  on  opposite  sides  of 
the  Christian's  path,  they  lead  to  the  same  result  ; 
and  if  once  enticed  from  the  narrow  way,  the  Chris- 
tian will  be  fortunate  if  Faith  rescues  him  from  the 
peril  before  he  plunges  utterly  into  the  gulf  of 
atheism.  We  must  not  confound  the  Creator  with 
the  creature.  There  is  a  personal  God  above  all 
and  over  all,  and  although  nature  manifests  His 
intelligence,  its  material  forms  are  only  the  reflec- 
tion, not  the  substance,  of  His  Being.  The  error 
of  the  pantheist  arises  from  a  too  superficial  study 
of  nature,  and  if  we  examine  more  closely  the  anal- 
ogies between  the  laws  of  nature  and  the  results 
of  human  thought,  I  am  confident  we  shall  find 
that  the  created  forms  may  be  readily  distin- 
guished from  the  Intelligence  which  gave  them 
being. 

In  every  human  work,  we  may  always  distin- 
guish two  things,  the  conception  and  the  execu- 
be-  ^ouy  an(^  ^ne  ^as^  never  exactly  conforms 
to  the  first.     For  example,  in  one  of  the 


ception  and  the  -i      /•>«       i   •  111  r» 

execution  of  a  grand  Gothic  cathedrals  of  our  mother 
country  we  see  united  in  the  plan,  first, 
the  idea  of  the  cross,  the  emblem  of  our  Christian 
faith;  then  the  spire,  typifying  the  aspiration  of 
the  soul  ;  and  lastly,  the  long  aisles,  whose  pointed 
arches  and  delicate  tracery  have  been  copied  from 
the  interlacing  branches  of  God's  first  temple.  The 
combination  of  these  ideas  may  be  said  to  be  the 


LECT.  X.]  ARGUMENT   FROM   GENERAL   PLAN.  307 

i 

conception  of  the  cathedral ;  but  how  differently 
has  this  conception  been  embodied  in  the  numer- 
ous cathedral  churches  of  England !  Besides  the 
peculiar  caprices  of  the  architect  or  builder,  we  can 
trace  in  each  church  an  evident  adaptation  of  the 
parts  to  special  purposes.  Here  a  "  lady  niustrated  by 
chapel"  has  been  included  in  the  design,  architecture- 
and  here  the  mausoleum  of  a  king  or  a  prelate ; 
here  a  portion  has  been  adapted  to  the  reading  of 
the  service,  and  here  to  the  session  of  the  ecclesias- 
tical court ;  but  however  varied  the  execution,  the 
same  conception  is  evident  in  all.  So  it  is  in  all 
architecture.  Our  modern  dwellings  are  built  after 
a  few  general  types,  and  the  conception  is  very 
nearly  the  same  in  all  houses  of  any  one  class. 
But  how  differently  a  skilful  architect  will  arrange 
the  details,  and  adjust  them  to  the  circumstances 
of  the  location,  to  the  wants  of  the  family,  or  the 
taste  of  the  owner !  and  no  one  knows  better  than 
he  that  the  conception  of  the  building  is  one  thing, 
and  the  execution  of  that  conception  a  very  dif- 
ferent thing. 

In  the  higher  forms  of  art,  the  same  truth  ap- 
pears even  more  strikingly.     The  Transfiguration 
of  Raphael,  that  masterpiece  of  painting,  mutated 
does  not  hold  you  breathless  before  it  so  inart> 
much  by  what  it  actually  represents,  as  by  what  it 
embodies  and  helps  you  to  realize.     He  who  sees 
merely  what  is  painted  on  the  canvas  will   turn 
away  disappointed,  but  in  the  soul  of  the  true  stu- 
dent of  art,  who  enters  into  the  spirit  of  the  great 


308  RELIGION   AND    CHEMISTRY.  [LECT.  X. 

painter,  the  conception  grows  as  he  gazes,  until  he 
becomes  transported  and  gains  a  vision  of  the  splen- 
dor of  the  Mount.  In  like  manner,  it  is  not  that 
lovely  female  face  which  has  endeared  the  Sistine 
Madonna  to  so  many  hearts,  and  made  Dresden  one 
of  the  shrines  of  the  world.  In  mere  point  of  exe- 
cution this  picture  may  be  surpassed  by .  many 
works  of  living  artists ;  but  the  conception  of  a  pure 
mother's  love  has  been  nowhere  embodied  as  there, 
and  that  is  the  charm.  You  stand  before  the 
Laocoon  until  the  blood  grows  cold  and  the  muscles 
writhe  in  sympathy,  and  then  you  look  at  the 
motionless  statue  and  wonder  whence  comes  the 
power.  It  is  not  in  the  skilfully  chiselled  marble, 
but  it  is  in  the  conception  of  the  unknown  artist, 
which  the  petrified  forms  suggest.  So  it  is  every- 
where with  the  works  of  man;  the  conception  can 
always  be  distinguished  from  the  embodied  fact. 
But  what  need  of  illustration?  Who  does  not 
know  the  difference  between  the  two,  and  who 
has  not  sadly  experienced  how  far  his  best  efforts 
fall  short  of  his  ideal  ?  The  thought,  the  concep- 
tion, how  noble  !  the  execution,  the  reality,  how 
humble ! 

Turning  now  to  Nature  we  find  the  same  distinc- 
tion there  between  the  conception  and  the  facts. 
Nature  does  not,  of  course,  like  man,  fall 

The  same 

distinction       below  her  ideal  for  want  of  power,  but 

she  departs  from  it  in  order  to  adapt  her 

works  to  specific  ends.     Everywhere  the  conception, 

or,  as  we  generally  call  it,  the  law,  is  modified  in  the 


LECT.  X.]  ARGUMENT   FROM   GENERAL  PLAN.  309 

execution  to  insure  special  adaptation.  We  may 
not  always  be  able  to  discover  the  adaptation,  but 
in  every  case  we  find  that  the  phenomena  do  not 
exactly  conform  to  the  law.  Keview  for  a  moment, 
with  this  idea,  the  few  examples  of  natural  laws 
which  I  have  so  briefly  sketched,  beginning  with 
the  law  of  symmetry. 

We  seldom,  if  ever,  find  in  nature  crystals  having 
that  regularity  of  form  or  that  perfection  of  outline 
represented  in  our  figures.     Natural  crys-  moated 
tals  are  invariably  more  or  less  distorted  bycrystals- 
or  imperfect.     You  would  hardly  believe  the  crys- 
tal represented  by  Fig.  23  to  be  an  octahedron, 
and  yet  it  is  merely  this  familiar 
form  somewhat  distorted.     I  ad- 
mit that  the  distortion  in  this 
case  is  unusually  great ;  —  still  a 
perfect  crystal  is  at  best  a  very 
rare  exception.     It  is  true  that 
in  all  cases  of  distortion  the  rel-  Fig  23< 

ative  inclination  of  the  planes 
is  very  nearly  constant ;  but  even  this  is  liable  to 
some  variation.  Moreover,  there  are  several  forms 
of  crystals  represented  in  these  diagrams,*  which 
are  never  found  in  their  perfection  in  nature.  They 
are  merely  shadowed  forth,  as  it  were,  on  other 
forms,  and  so  partially  that  the  unpractised  eye 
would  never  detect  them.  So  true  is  this,  that,  as 
I  have  before  stated,  the  present  science  of  crys- 
tallography could  never  have  been  developed  by 

*  See  the  three  groups  of  crystals  given  in  the  last  Lecture. 


310  RELIGION   AND    CHEMISTRY.  [LECT.  X. 

observation  alone.  How  evident,  then,  the  distinc- 
tion between  the  actual  crystals  and  the  thought 
which  they  embody ! 

Passing  next  to  chemistry,  we  notice  the  same 
truth  in  the  law  of  progression  by  series.  We  do 
mustrated  n°t  find  that  the  properties  of  the  ele- 
in  chemistry.  ments  in  any  of  the  series  given  in  the  ta- 
ble on  page  291  are  exactly  those  'required  by  the 
law;  but  in  each  case  they  approximate  more  or 
less  closely  to  the  ideal  type.  Thus,  if  the  law  were 
exactly  observed,  the  chemical  equivalents  would 
be  those  given  in  the  column  headed  Theoretical ; 
and  it  will  be  seen  that  these  numbers  by  no  means 
exactly  coincide  with  the  observed  equivalents, 
which  for  comparison  are  placed  at  the  side.  The 
same  is  true  of  the  other  properties  of  these  ele- 
ments. 

This  simple  law  of  relationship,  first  observed  by 
myself  over  ten  years  since,  has  been  questioned,  on 
the  ground  that  it  does  not  exactly  represent  the 
fact ;  and  Dumas,  of  Paris,  while  adopting  essentially 
the  same  system  of  classification,  has  modified  the 
details,  in  order  to  obtain  a  more  exact  conformity, 
carefully  redetermming  many  of  the  chemical  equiv- 
alents, with  the  evident  idea  that  they  must  exactly 
coincide  with  the  law.  But  surely,  if  we  may  rea- 
son by  analogy,  no  such  precision  was  to  be  expect- 
ed, and,  in  seeking  to  realize  this  illusion,  Dumas 
overlooked  the  simple  conception  and  substituted  a 
most  mechanical  and  improbable  system  in  its  place. 
It  was  never  supposed  that  the  facts  of  nature  would 


LECT.  X.]  ARGUMENT   FROM   GENERAL   PLAN.  311 

exactly  correspond  to  the  law;  for  it  was  known 
that  an  exact  correspondence  between  the  law  and 
the  phenomena  is  found  absolutely  nowhere.  All 
I  claimed  was,  that  with  the  various  elements  there 
was  a  general  conformity  in  their  properties  to  this 
simple  conception  of  series.  I  supposed  that  the 
properties  of  matter  had  been  distributed  according 
to  this  general  plan ;  but  at  the  same  time,  know- 
ing that  each  element  had  been  specially  adapted 
to  a  certain  specific  end,  I  did  not  expect  to  find 
the  conception  perfectly  realized. 

When  now  we  study  the  elements  from  this  point 
of  view,  we  at  once  notice  that  the  departure  from 
the  general  law  is  most  marked  in  those  substances 
which  are  most  widely  distributed  in  nature,  and 
where  the  special  adaptations  are  the  most  evident. 
This  is  especially  true  of  the  substances  composing 
the  atmosphere.  The  elements,  oxygen,  nitrogen, 
carbon,  and  hydrogen,  and  the  compounds,  water, 
ammonia,  nitric  acid,  and  carbonic  acid,  are  all  re- 
markably unique  substances,  and  were  we  to  exam- 
ine their  external  qualities  alone,  we  should  never 
discover  their  relationship ;  but  on  studying  careful- 
ly their  chemical  relations,  we  find  that,  while  they 
have  been  adapted  with  such  wonderful  skill  to  the 
important  ends  which  they  have  been  appointed  to 
subserve,  they  have  also  been  made  to  conform,  at 
least  in  their  main  features,  to  the  general  plan. 
There  is  still  another  point  connected  with  the  clas- 
sification of  the  elements  which  is  deserving  of  our 
notice  in  this  connection.  We  have  already  seen 


312  RELIGION   AND    CHEMISTRY.  [LECT.  X. 

that,  although  sixty-four  elements  have  been  discov- 
ered, the  greater  portion  of  the  earth's  crust  consists 
of  only  ten  or  twelve.  Indeed,  if  the  remaining 
fifty  elements  were  suddenly  annihilated,  the  mass 
of  the  globe,  so  far  as  we  know,  would  not  be  sensi- 
bly diminished.  Indeed,  a  large  number  of  the  ele- 
ments occur  only  in  some  of  the  rarest  minerals,  and 
there  in  such  minute  quantities  that  they  can  be 
detected  only  by  the  most  skilful  chemical  analysis. 
That  these  very  rare  elements  were  designed  by  the 
Creator  to  subserve  important  ends,  we  need  not 
doubt ;  but  it  is  certain  that  they  play  a  very  subor- 
dinate part  on  the  surface  of  the  globe.  For  bro- 
mine and  iodine,  and  a  few  others,  important  appli- 
cations have  been  discovered  in  the  arts  or  in  med- 
icine; but  the  rest,  comprising  at  least  one  third 
of  all  the  known  elements,  have  no  apparent  value 
except  as  parts  of  a  general  plan.  In  the  light  of 
a  utilitarian  philosophy  they  must  appear  useless ; 
but  to  the  true  student  of  nature  they  have  a  signif- 
icance which  transcends  everything  else.  They  are 
parts  of  a  universal  order,  of  a  Divine  cosmos,  which 
would  be  incomplete  without  them.  They  are  the 
manifestation  of  Infinite  Intelligence.  They  em- 
body the  thoughts  of  God.  Man's  material  wants 
and  pleasures  are  not  the  sole  end  of  creation.  In 
the  words  of  Chevalier  Bunsen,  "  Law  is  the  su- 
preme rule  of  the  universe,  and  this  law  is  intellect, 
is  reason,  whether  viewed  in  the  formation  of  a 
planetary  system  or  in  the  organization  of  a  worm." 
But  we  must  remember,  in  discussing  this  ques- 


LECT.  X.]  ARGUMENT   FROM    GENERAL   PLAN.  313 

tion,  that  it  does  not  follow,  because  we  cannot  dis- 
cover any  important  end  which  these  elements  sub- 
serve on  our  earth,  that  they  have  no  practical 
utility.  For  after  acknowledging  the  dignity  which 
they  acquire  when  regarded  as  the  characters  of 
that  language  in  which  the  creative  thoughts  have 
been  written,  and  as  the  appointed  means  of  edu- 
cating the  human  race,  still  it  does  not  seem  con- 
sistent with  that  economy  of  resources  which  ap- 
pears in  all  parts  of  the  Divine  plan,  that  they 
should  have  no  special  functions  to  discharge  in  the 
cosmos.  Now  I  would  suggest,  but  I  offer  the  sug- 
gestion in  all  humility,  that  these  very  rare  elements 
may  be  adapted  by  their  peculiar  properties  to  the 
thermal  conditions  of  some  other  planet  or  some 
other  stellar  system.  We  have  seen  that  those  ele- 
ments which  are  the  most  widely  distributed  over 
the  earth  are  such  as  are  adapted  by  their  proper- 
ties to  the  conditions  of  organic  life  on  the  third 
planet  of  the  solar  system,  and  it  is  certainly  pos- 
sible that  some  different  scheme  of  organic  life  may 
be  sustained  on  Mercury  or  Uranus,  in  which  ele- 
ments rare  to  us  take  the  place  of  oxygen,  nitrogen, 
hydrogen,  and  carbon,  and  perhaps  also  the  ele- 
ments missing  in  our  classification  may  be  found  in 
some  other  world,  revolving  around  Sirius  or  Arc- 
turns,  where  oxygen,  sulphur,  and  iron  may  be 
among  the  rarities  of  science. 

All  this  is  of  course  the  purest  hypothesis,  and 
such  speculation  can  lead  to  no  positive  results ;  but 
the  very  possibility  of  the  speculation  illustrates 


314  RELIGION   AND    CHEMISTRY.  [LECT.  X. 

most  pointedly  the  great  truth  which  I  am  endeav- 
oring to  enforce.  The  thought  which  is  embodied 
in  the  scheme  of  the  chemical  elements  is  some- 
thing entirely  apart  from  their  material  forms,  and 
the  moment  this  thought  is  apprehended  by  man,  it 
opens  to  his  imagination  vistas  of  possible  realities 
which  entirely  transcend  all  human  experience. 

If  next  we  compare,  more  carefully  than  before, 
the  periods  of  revolution  of  the  planets  around  the 
Diustrated  m  Sun,  we  shall  find  that  the  same  principle 
astronomy.  holds  true.  The  observed  periods,  you 
will  notice  by  the  table  on  page  299,  do  not  exact- 
ly correspond  to  the  simple  ratios  which  express 
the  law,  and  the  same  is  true  of  the  distribution  of 
leaves  around  the  stem  of  a  plant,  and  in  fact  of  all 
classes  of  phenomena  in  nature.  In  each  we  ob- 
serve only  a  tendency  towards  a  maximum  effect, 
which  is  the  perfect  expression  of  the  law,  but 
which  is  seldom  fully  reached.  The  limits  of  varia- 
tion are  broader  in  some  cases  than  in  others,  but 
we  find  no  case  in  which  the  accordance  is  absolute. 

In  none,  however,  of  the  purely  physical  laws 

is   this   character   so   strongly  marked  as   in   the 

structure  of  animals  and  plants.     It  is  well 

Illustrated  in  i 

botany  and  known  that  all  organized  forms,  although 
so  wonderfully  diversified,  are  fashioned 
after  a  few  general  types.  In  the  animal  kingdom 
there  are  only  four  general  plans,  represented  by 
the  Radiata,  the  Mollusca,  the  Articulata,  and  the 
Vertebrata,  and  all  the  animals  of  any  one  of  these 
great  divisions  are  organized  alike.  For  example, 


LECT.X.]  ARGUMENT   FROM   GENERAL   PLAN.  315 

in  all  vertebrate  animals  we  find  essentially  the 
same  parts,  and  frequently  where  there  is  no  use 
for  a  given  organ  it  is  still  present  in  a  rudimen- 
tary condition.  Professor  Wyman  has  found  rudi- 
mentary eyes  in  the  so-called  eyeless  fish  of  the 
Mammoth  Cave,  and  any  anatomist  will  point  out 
to  you  in  the  skeleton  of  a  fish,  of  a  reptile,  of  a 
bird,  or  of  a  quadruped,  the  bones  which  correspond 
to  the  various  parts  in  the  skeleton  of  a  man.  In 
the  wing  of  a  bat  the  bones  of  the  human  arm  may 
readily  be  traced. 

Here  then  is  a  most  obvious  distinction  between 
the  conception  and  the  execution,  and  the  general 
plan  of  the  skeleton  is  preserved  even  where  there 
is  no  use  for  certain  parts,  and  where  we  might 
perhaps  conceive  of  a  simpler  arrangement  without 
them.  But,  more  than  this,  we  find  that  the  varia- 
tions from  what  we  may  regard  as  the  typical  form 
have  been  obviously  made  in  order  to  adapt  the 
organs  to  certain  specific  ends.  The  same  plan 
which,  developed  in  its  full  perfection,  appears  iu 
the  human  hand  and  arm,  reappears,  more  or  less 
fully  carried  out,  in  the  fore  legs  of  a  horse,  in  the 
wings  of  an  eagle,  and  in  the  pectoral  fins  of  a  dol- 
phin ;  and  in  each  case  the  organ  has  been  obviously 
adapted  to  some  special  purpose.  Special  adapta- 
tion has  thus  been  most  beautifully  harmonized 
with  general  law,  and  the  conception  has  been  va- 
ried in  the  execution  in  order  to  secure  some  wise 
and  important  end.  So  also  it  may  be  that,  when 
in  the  laws  of  inorganic  nature  we  cannot  discover 


316  RELIGION   AND    CHEMISTRY.  [LECT.  X. 

the  cause  of  a  variation,  a  similar  wise  purpose  is 
concealed. 

This  subject  is  capable  of  almost  indefinite  illus- 
tration, and  the  vegetable  kingdom  is  as  rich  in 
examples  of  the  principle  we  have  been  discussing 
as  the  animal.  I  have  not,  however,  time  for  fur- 
ther details.  The  whole  ground  has  been  most 
carefully  surveyed  by  McCosh  and  Dickie  in  their 
excellent  work  entitled  "  Typical  Forms  and  Special 
Ends  in  Creation,"  and  to  this  I  would  refer  those 
who  may  be  interested  to  pursue  the  study  of  these 
singular  facts.  Sufficient,  I  trust,  has  already  been 
said  to  show  that  the  phenomena  of  nature  and  the 
results  of  human  thought  resemble  each  other  in 
their  very  incompleteness. 

While,  therefore,  a  more  careful  study  has  tended 

to  confirm  the  result  at  which  we  arrived  in  the 

last  Lecture,  and   has   strengthened  the 

Nature  points 

to  a  personal  impression  that  the  universe  was  created 
by  an  intelligence  like  our  own,  we  have 
also  found  that  the  analogies  of  nature  point  with 
equal  distinctness  to  the  conclusion  that  this  intel- 
ligence is  a  being  entirely  apart  from  and  infinitely 
superior  to  the  matter  he  created  or  the  laws  he 
ordained.  If  these  analogies  are  worth  anything, 
they  point  not  to  a  supreme  spirit  of  the  universe, 
pervading  and  energizing  matter,  but  they  prove  the 
existence  of  a  personal  God ;  one  who  can  sustain 
to  us  the  relations  of  Father,  Saviour,  and  Sanctifier ; 
one  whom  we  can  love,  worship,  and  adore. 

But  it  may  be  urged  that  I  have  drawn  my  illus- 


LECT.  X.]  ARGUMENT   FROM    GENERAL   PLAN.  317 

trations  wholly  from  the  phenomenal  laws  of  na- 
ture, and  entirely  overlooked  the  great  dynamical 
laws,  which,  like  the  law  of  gravitation,  are  more 
precise.  Moreover,  it  will  be  said  that  the  history 
of  astronomy  gives  us  every  reason  to  believe  that 
these  very  variations  to  which  I  have  given  such 
importance  are  merely  necessary  consequences  of 
some  higher  law  not  yet  discovered,  just  as  the  per- 
turbations of  the  planetary  orbits  are  the  legitimate 
results  of  the  very  law  they  seem  at  first  to  invali- 
date. I  have  no  doubt  that  in  part,  at  least,  this  will 
be  found  to  be  the  case.  But  even  in  regard  to  the 
law  of  gravitation,  there  always  have  been  residual 
phenomena,  unexplained  by  the  law,  and  so  prob- 
ably there  always  will  be,  until,  as  we  go  on  widen- 
ing our  generalizations,  the  last  generalization  of 
all  brings  us  into  the  presence  of  that  First  Cause 
through  whom  and  by  whom  all  things  are  sus- 
tained. 

I  trust  that  the  striking  analogies  between  the 
phenomena  of  nature  and  the  results  of  human 
thought,  which  I  have  been  able  so  imper-  Forceofthe 
fectly  to  illustrate,  have  impressed  you,  as  ar^ument- 
they  impress  me,  with  the  profound  conviction  that 
the  order  of  nature  is  the  manifestation  of  an  Infi- 
nite Intelligence,  but  of  an  Intelligence  apart  from, 
and  superior  to,  the  order  which  it  once  created 
and  now  upholds.  If  I  have  failed  in  my  object,  it 
is  because  I  have  been  unable  to  bring  home  these 
analogies  to  your  understanding.  The  resemblances 
are  so  striking,  that  I  do  not  believe  a  mind  which 


318  RELIGION  AND    CHEMISTRY.  [LECT.  X. 

is  conversant  with  the  facts,  and  unbiassed  by  the 
prejudices  of  philosophy  or  of  education,  can  re- 
sist the  conclusion  that  this  scheme  of  nature  is 
the  manifestation  of  an  intelligence  like  our  own, 
at  least  so  far  as  the  Infinite  can  be  said  to  re- 
semble the  finite.  Men  may  reasonably  entertain 
differences  of  opinion  in  regard  to  the  mode  of 
action  of  that  Being  who  has  created  the  universe. 
They  may  believe  that  a  certain  amount  of  power, 
together  with  the  germ  of  all  future  existence,  was 
implanted  in  the  original  chaos,  and  that  the  Deity 
has  never  interfered  with  the  natural  action  and 
the  unfolding  of  the  causes  which  He  has  thus  or- 
dained ;  but  whatever  theories  of  cosmogony  may 
be  entertained,  short  of  absolute  materialism,  he 
must  be  indeed  blinded  by  his  prejudices  who  re- 
fuses to  recognize  in  these  analogies  the  evidence 
of  intelligence  and  thought. 

I  do  not  of  course  regard  analogies  as  proofs,  nor 
do  I  believe  that  this  argument  from  general  plan 
it  is  subsidiary  could  suppty  the  place  of  the  great  argu- 
to  the  argu-  ment  from  design.  The  last  lies  at  the 

merit  from 

special  adap-  basis  of  Natural  Theology,  and  all  the 
rest  is  merely  subsidiary  to  the  great  cen- 
tral light.  Moreover,  while  the  argument  from  de- 
sign comes  home  to  every  man's  understanding, 
these  analogies  appeal  with  their  full  force  only  to 
the  few  who  are  able  to  study  the  processes  of  na- 
ture for  themselves ;  as  they  alone  are  familiar  with 
the  phenomena  in  which  the  resemblances  are  seen. 
But  to  the  student,  whose  life  has  been  passed  in 


LECT.X.]     ARGUMENT  FROM  GENERAL  PLAN.        319 

successful   investigation,  and  whose  soul  has  been 
brought  into  sympathy  with  the  harmo- 

J  Appeals  es- 

nies  of  nature,  these  tokens  are  constantly  Peciaiiyto 
assuring  him  of  the  presence  of  his  God. 
Every  discoverer  feels  —  when  in  the  presence  of  a 
great  truth,  he  cannot  resist  the  feeling  —  that,  in 
discovering  a  law,  he  has  been  brought  nearer,  not 
to  a  blind  agency,  but  to  Omnipotence  itself.  To 
this  conclusion  he  is  not  led  solely  by  philosophy ; 
for  although  he  may  defend  his  conviction  on  rea- 
sonable grounds,  in  its  full  power  it  transcends  all 
human  philosophy.  Man  cannot  always  tell  why 
he  knows.  But  when  illuminated  from  the  altar 
of  his  faith  all  nature  wears  a  new  aspect,  and 
his  spiritual  eye  discovers  everywhere  acting 
that  same  Infinite  Intelligence  which  "  spake  in 
"time  past  unto  the  fathers  by  the  prophets," 
and  "hath  in  these  last  days  spoken  unto  us  by 
"his  Son." 

Do  I  hear  it  said  that  such  loose  reasoning  is  a 
gross  violation  of  the  Baconian  philosophy,  and  of 
that  severe  induction  by  which  alone  science  has 
been  built  up  ?  But  do  we  not  know,  have  we  not 
seen,  that  the  whole  structure  of  science  rests  on 
no  firmer  foundation  than  these  very  analogies  of 
nature,  —  that  at  the  beginning  of  all  knowledge, 
where  we  should  most  expect  infallibility,  we  find 
only  uncertainty  and  doubt  ? 

Science  is  a  grand  temple  built  by  man  to  glorify 
his  Maker,  its  unfinished  spire  pointing  to  heaven, 
but  its  foundations  resting  on  a  cloud.  The  work 


21 


320  RELIGION   AND    CHEMISTRY.  [LECT.  X. 

has  been  done  as  well  as  faithful  hearts  and  active 
hands  could  do  it.  Examine  its  walls  and  its  but- 
tresses, and  from  base-stone  to  coping  you  will  find 
no  defect.  Each  block  has  been  so  carefully 
wrought  and  so  firmly  clamped  in  its  place,  with 
all  the  strength  of  iron  logic,  that  you  will  unhesi- 
tatingly conclude  that  the  mighty  structure  has 
been  raised,  not  for  time,  but  for  eternity.  Yet  all 
rests  on  a  cloud.  Let  that  cloud  be  dispersed,  and 
only  God  can  tell  whether  that  structure  shall  stand 
or  fall. 

Are  we  then,  you  will  ask,  to  mistrust  these 
boasted  results  of  science  ?  Is  this  imposing  struc- 
ture all  a  phantom,  a  mere  day-dream,  from  which 
we  shall  awake  on  the  morning  of  eternity  to  find 
all  passed  ?  Certainly  not !  God  has  not  endowed 
his  creature  with  faculties  of  observation  merely 
to  deceive  him,  and  with  an  intellect  solely  to  lead 
him  into  error.  He  has  not  raised  up  the  long  line 
of  scientific  heroes  of  every  age,  merely  to  deceive 
themselves  and  mislead  the  world.  No  !  the  temple 
of  science  will  stand  fast.  That  cloud  on  which  it 
rests  is  a  firmer  foundation  than  any  granite  rock ; 
for  it  is  not  of  man,  but  of  God.  Yet  let  us  not  for- 
get that  this  assurance  is  based  only  on  the  same 
faith  which  is  the  "  substance  of  things  hoped  for, 
"  the  evidence  of  things  not  seen." 

"  We  have  but  faith  :  we  cannot  know  ; 
For  knowledge  is  of  things  we  see ; 
And  yet  we  trust  it  comes  from  Thee, 
A  beam  in  darkness :  let  it  grow." 


LECT.  X.]  ARGUMENT   FROM   GENERAL   PLAN.  321 

I  have  endeavored  in  these  Lectures  to  show  that 
the  evidence  which  all  nature  affords  of  a  personal 
God,  is  wholly  independent  of  the  theories  of  cos- 
mogony we  may  assume.  But  although  our  doc- 
trine of  causation  may  not  impair  the  evidence  of  an 
original  design,  it  is  not  so  with  the  other  bearings 
of  the  subject.  For  if  nature  be  a  mere  machine, 
weaving  the  complex  web  of  destiny  with  the  same 
precision  and  certainty  with  which  a  carpet-loom 
weaves  the  pattern  of  a  carpet,  then  the  Christian's 
idea  of  a  superintending  Providence  cannot  be  true. 
If  nature  has  been  evolved  solely  under  necessary 
conditions  and  laws,  with  which  the  Creator  has 
never  interfered  since  he  wound  up  the  immense 
weight  which  set  the  whole  in  motion  and  still 
maintains  the  preordained  beats  of  the  great  pendu- 
lum of  the  universe, — if  with  an  archangel's  intellect 
we  could  predict  every  event  in  nature  with  the  same 
certainty  with  which  we  now  foretell  the  phases  of 
an  eclipse,  —  then  I  say  again  that  the  visions  of  an 
overshadowing  Providence,  which  have  appeared  to 
us  at  those  milestones  on  our  life's  journey  where, 
wearied  and  disheartened,  we  have  sat  down  to  rest, 
are  nothing  but  a  delusion  and  a  dream.  It  does  not 
remove  the  difficulty  here  referred  to,  to  say  that  our 
lives  are  parts  of  this  preordained  plan,  or  even  to 
admit  that  God  may  interfere  in  the  moral  world  by 
influencing  the  will  of  man ;  for  every  one  is  con- 
scious that  his  will  has  not  been  thus  directly  influ- 
enced, and  knows,  moreover,  that  the  circumstances 
of  his  condition  have  always  concealed,  at  the  time, 


322  KELIGION   AND    CHEMISTRY.  [LECT.  X. 

the  kind  Providence  by  which  he  has  been  led.  And 
when  your  theory  leads  to  this,  that  man  has  been 
put  into  a  world  of  probation  and  trial  and  there  left 
to  walk  over  pitfalls  with  his  eyes  blinded,  every  unso- 
phisticated mind  will  feel  —  say  what  you  will — that 
the  character  of  the  God  you  worship  is  more  truly 
symbolized  by  the  Juggernaut  car  than  by  the  cross. 
I  think  that  a  great  deal  of  false  prejudice  against 
scientific  study  arises  from  a  mistaken  impression 
that  the  materialist's  interpretation  of  nature  is  the 
natural  and  necessary  result  of  all  scientific  thought. 
Hence  not  a  few  religious  minds  have  concluded 
that  the  methods  of  science  must  be  all  wrong,  and 
its  conclusions  wholly  untrustworthy.  It  will  not, 
therefore,  be  out  of  place  in  this  connection  to  con- 
sider briefly  whether  the  materialist's  idea  of  causa- 
tion is  the  necessary,  or  even  the  probable,  conclu- 
sion to  which  the  observed  facts  of  nature  and  the 
legitimate  methods  of  science  lead.  We  must  re- 
member, however,  while  discussing  this  subject,  that 
we  have  passed  the  limits  of  human  knowledge,  and 
cannot  therefore  expect  by  our  unaided  processes 
of  thought  to  prove  or  disprove  anything.  We  can- 
not determine  absolutely  whether  the  materialist's 
theory  be  true  or  false  ;  for  science  has  not  the 
knowledge  which  would  enable  it  to  form  a  decision. 
The  only  question  for  us  is,  whether  this  theory  is 
the  necessary  theory,  or  even  the  most  probable 
theory ;  and  if  it  is  not  either  the  one  or  the  other, 
then  the  theory  is  of  no  weight.  One  man's  theory 
is  as  good  as  another's,  provided  both  are  equally 


LECT.  X.]  ARGUMENT   FROM    GENERAL   PLAN.  323 

consistent  with  facts.  If,  then,  we  can  show  on  sci- 
entific grounds  alone  that  the  Christian's  theory 
of  causation  is  as  probable  as  the  materialist's,  we 
shall  in  regard  to  this  point  also  fully  vindicate  the 
religious  character  we  have  constantly  claimed  for 
scientific  studies.  Surely  science  is  no  more  respon- 
sible for  the  excesses  of  theorists  than  is  religion 
for  the  crimes  of  bigots,  and  it  should  be  sufficient 
to  satisfy  any  religious  mind,  that  there  is  a  Chris- 
tian theory  which  is  perfectly  consistent  with  all 
known  facts. 

It  is  easy  to  understand  the  relative  position  of 
the  two  theories  of  causation  after  we  have  become 
acquainted  with  the  facts  which  both  must  neces- 
sarily explain.  Let  us  review,  then,  very  briefly, 
these  facts,  which  are  more  or  less  familiar  to  every 
one.  An  innate  principle  of  the  human  mind  forces 
upon  us  the  conclusion  that  every  change  must 
have  an  adequate  cause,  and  leads  us  to  refer  the 
phenomena  of  nature  to  what  we  call 
forces.  Thus  the  falling  of  an  avalanche, 
the  flowing  of  the  tides,  the  beating  of  the  waves, 
the  blowing  of  the  winds,  the  crashing  of  the  light- 
ning, the  burning  of  the  fire,  the  moving  power  of 
steam,  and  the  impression  of  light,  must  all  have  an 
adequate  cause,  and  to  this  cause  we  give  the  name 
of  force.  We  use  this  word  so  frequently  and  so 
familiarly  that  we  are  apt  to  think  that  we  associate 
with  it  a  definite  conception ;  but  a  moment's  reflec- 
tion will  show  that,  in  regard  to  the  nature  or  ori- 
gin of  force,  we  have  no  absolute  knowledge.  This 


324  RELIGION   AND    CHEMISTRY.  [LECT.  X. 

word  is  merely  our  name  for  the  unknown  cause  of 
natural  phenomena.  The  uneducated  mind  natu- 
rally refers  the  origin  of  all  force  to  the  bodies 
from  which  it  appears  to  emanate,  and  regards  it 
either  as  a  quality  inherent  in  matter,  as  in  the 
phenomena  of  gravitation,  or  as  a  property  super- 
imposed upon  matter,  as  in  the  phenomena  of  light, 
heat,  magnetism,  and  electricity.  In  either  case, 
however,  it  is  regarded  as  a  quality  of  matter.  More- 
over, the  uneducated  mind,  impressed  most  of  all 
by  the  great  diversity  in  physical  phenomena,  natu- 
rally infers  that  a  similar  diversity  exists  in  the 
force  which  produces  them,  and  thus  is  led  to  the 
idea  that  there  are  different  kinds  of  force.  Hence 
men  have  been  led  to  refer  the  falling  of  bodies 
towards  the  earth  to  a  distinct  force  called  gravita- 
tion, the  motion  of  a  steam-engine  to  another  force 
called  heat,  the  burning  of  a  candle  to  a  third  force 
called  chemical  affinity,  and  in  like  manner  to  each 
class  of  phenomena  they  have  assigned  a  peculiar 
and  separate  force. 

Such  ideas  as  these  are  natural  in  the  infancy  of 

knowledge,  and  we  must  remember  that,  with  all  our 

boast  of  progress,  the  human  race,  so  far  at 

Language  of  r       °    .        ;  . 

Bdence  liable  least  as  physical  science  is  concerned,  is 
yet  in  its  childhood.  The  law  of  gravita- 
tion was  discovered  only  a  century  and  a  half  ago, 
and  almost  the  whole  of  the  present  sciences  of 
chemistry  and  physics  has  been  developed  within 
the  lifetime  of  men  now  living.  The  present  genera- 
tion were  educated  in  those  very  natural,  but  crude 


LECT.X.]  ARGUMENT   FROM   GENERAL   PLAN.  325 

notions,  and  it  is  not  until  a  comparatively  recent 
period  that  even  scientific  men  have  been  persuaded 
that  these  primitive  ideas  must  be  wholly  aban- 
doned, or  at  least  radically  modified.  We  are  now 
in  a  transition  stage,  and  hence  arises  a  great  diffi- 
culty in  discussing  the  subject.  The  language  even 
of  modern  science  is  based  upon  the  old  ideas,  and 
we  cannot  describe  natural  phenomena  without  us- 
ing terms  which  imply  what  almost  all  thinkers  now 
believe  to  be  erroneous  notions.  Hence,  when  we 
attempt  to  present  spiritual  views  of  the  origin  and 
nature  of  force,  we  are  obliged  to  use  terms  which 
imply  the  opposite,  and  our  very  language  appears 
to  condemn  us,  or  at  least  prejudices  our  theory. 
This  is  especially  true  of  the  word  force,  and  we 
must  carefully  bear  in  mind  that  the  origin  of  phe- 
nomena is  not  explained,  because,  in  the  language 
of  science,  they  have  been  referred  to  an  assumed 
force  with  a  high-sounding  name.  Names  are  not 
things,  and  we  know  nothing  more  of  the  cause 
which  brings  the  apple  to  the  ground  because  New- 
ton has  called  it  the  force  of  gravitation,  than  we 
did  before.  He  gave  us  the  law  of  the  motion,  and 
enabled  us  to  predict  how  every  apple  would  fall, 
and  how  every  planet  would  move  throughout 
space,  but  the  cause  of  the  motion  is  as  closely  hid- 
den as  ever.  In  regard  to  the  law  of  gravitation  we 
know  a  great  deal ;  but  in  regard  to  the  force  of 
gravitation  —  whatever  we  may  think  or  believe 
about  it  —  we  know  absolutely  nothing,  and  the 
same  is  true  of  every  other  force. 


326  RELIGION   AND    CHEMISTRY.  [LECT.  X. 

The  most  remarkable  feature  of  modern  science 
has  been  the  constant  tendency  of  all  investigation, 
Transferor  during  the  last  fifty  years,  to  show  that 
energy.  faQ  same  energy,  if  only  differently  ap- 
plied, may  produce  the  most  diversified  phenom- 
ena ;  and  now  almost  all  the  so-called  forces  of  the 
old  philosophy  appear  to  be  mutually  convertible. 
Thus  —  to  begin  with  a  lump  of  coal  —  as  we  have 
seen,  a  certain  amount  of  latent  energy  resides  in 
that  black  mass,  which  has  been  called  the  force  of 
chemical  affinity.  Burn  the  coal,  —  that  is,  com- 
bine it  with  oxygen,  —  and  the  affinity  is  satisfied, 
but  the  energy  reappears  as  light  and  heat.  If  the 
coal  is  burnt  under  a  steam-boiler,  the  heat  expands 
the  water  and  converts  it  into  vapor,  and  then  we 
find  the  energy  again  in  the  expansive  force  of 
steam.  The  steam  expands  against  the  piston  of 
the  locomotive,  and  the  energy  passes  into  the 
moving  train.  The  rapidly  moving  mass,  in  forcing 
its  way  through  the  air  and  over  the  iron  track,  is 
constantly  losing  its  moving  power  in  consequence 
of  the  friction  it  encounters ;  but  the  energy  is  not 
lost,  and  if  we  could  follow  it,  we  should  find  it  re- 
appearing somewhere  as  heat.  Suddenly  the  engi- 
neer opens  a  valve,  and  a  portion  of  the  energy  of 
the  steam  gives  motion  to  the  air,  and  the  effect  is  a 
shrill  whistle.  The  brakeman  applies  the  brakes,  and 
the  train  after  a  few  moments  comes  to  rest.  Its 
moving  power  is  gone,  but  the  energy  is  not  lost. 
The  motion  has  been  transformed  into  heat,  and  the 
smoking  brake  shows  where  the  energy  has  gone. 


LECT.  X.]  ARGUMENT   FROM   GENERAL   PLAN.  327 

Return  now  again  to  the  lump  of  coal,  and,  in- 
stead of  burning  it  under  a  steam-boiler,  heat  it 
in  a  properly  constructed  furnace  in  contact  with 
roasted  zinc  ore.  This  ore  is  a  compound  of  zinc 
and  oxygen.  The  coal,  in  order  to  satisfy  its  in- 
tense affinity,  seizes  on  the  oxygen  and  sets  the 
zinc  free.  But  although  the  chemical  affinity  of 
the  coal  has  been  satisfied,  no  power  has  been  lost ; 
for  the  energy  which  was  before  latent  in  the  car- 
bon is  now  latent  in  the  zinc.  Dissolve  now  the 
zinc  in  dilute  sulphuric  acid,  and  the  chemical  affin- 
ity of  the  zinc  will  be  satisfied,  and,  if  certain  con- 
ditions are  fulfilled,  the  energy  will  take  the  form 
of  a  current  of  electricity.  Cause  this  current  to 
flow  through  a  platinum  wire,  and  this  energy  will 
appear  in  the  heat  and  light  radiated  from  the 
glowing  metal.  Cause  the  same  current  to  flow  in 
spiral  lines  around  a  bar  of  iron,  and  we  find  the 
energy  again  in  the  attractive  force  of  an  electro- 
magnet. Connect  with  the  electro-magnet  appro- 
priate machinery,  and  the  same  energy  may  be  so 
applied  that  it  will  move  a  light  boat  or  turn  a 
small  lathe.  Lastly,  connect  with  the  dissolving 
zinc  four  thousand  miles  of  iron  wire,  and  the  en- 
ergy will  be  transmitted  across  a  continent  with 
the  velocity  of  thought,  and  write  in  a  distant  city 
the  message  which  it  carries. 

Start  next  from  another  point.  What  could  be 
more  dissimilar  than  magnetism  and  light  ?  Yet 
a  magnet  may  be  made  the  means  of  producing  a 
most  brilliant  light.  When  we  apply  steam,  or  any 


328  RELIGION   AND    CHEMISTRY.  [LECT.  X. 

other  force,  to  turn  a  large  magneto-electric  ma- 
chine, the  moving  power  is  transmuted  by  the  steel 
magnets  into  a  powerful  electric  current.  If  now 
this  current  is  made  to  pass  through  the  air  be- 
tween two  charcoal  points  placed  near  together, 
the  particles  of  coal  become  most  intensely  ignited, 
and  emit  a  light  which  is  comparable  with  that  of 
the  sun.*  The  same  current,  if  passed  through  a 
quantity  of  water,  will  slowly  decompose  the  liquid, 
and,  while  forcing  the  hydrogen  apart  from  the 
oxygen,  will  transfer  a  portion  of  its  own  energy 
to  the  escaping  gases,  in  which  the  power  will 
remain  latent  until  the  elements  again  unite. 

Illustrations  like  these  might  be  multiplied  in- 
definitely ;  but  enough,  I  think,  has  been  said  to 
show  that,  to  all  appearance  at  least,  the  same  en- 
ergy may  be  transferred  from  one  mass  of  matter  to 
another,  and  that  thus,  while  nothing  but  the  mode 
of  application  has  been  changed,  the  power  may 
reappear  under  entirely  different  manifestations,  and 
produce  phenomena  wholly  unlike  those  in  which 
it  was  but  a  moment  before  the  active  cause.  The 
truth  of  this  principle  becomes  still  more  evident 
when  we  apply  in  our  experiments  exact  measure- 
ments ;  for  we  find  that  in  all  these  transfers  of 
energy  from  mass  to  mass  the  power  reappears  un- 
diminished.  It  may  remain  latent  for  a  time,  as  in 
a  mass  of  coal,  but  sooner  or  later  it  will  reappear 
without  having  undergone  the  slightest  loss. 

*  It  has  been  proposed  to  use  this  method  of  illumination  in  some  of 
the  lighthouses  on  the  English  coast. 


LECT.  X.]  ARGUMENT   FROM   GENERAL   PLAN.  329 

We  must  here  dwell  for  a  moment  upon  an  im- 
portant distinction,  which  has  already  been  implied, 
between  latent  and  active  energy.  It  is  Latentand 
a  distinction  with  which  every  one  is  prac-  active  energy> 
tically  familiar,  and  it  may  therefore  be  made  clear 
by  referring  to  a  few  examples.  A  weight  falling 
to  the  ground  from  a  given  height  is  an  example 
of  active  energy,  while  an  equal  weight  suspended 
at  the  same  height  represents  an  equivalent  amount 
of  latent  energy.  In  winding  up  a  clock,  muscular 
energy  becomes  latent  in  the  suspended  weight, 
but  reappears  in  mechanical  motion  as  the  clock 
runs  down.  So  also  a  lump  of  coal,  as  already 
stated,  represents  a  certain  amount  of  latent  en- 
ergy. When  the  coal  burns,  its  energy  becomes 
active,  and  takes  the  form  of  heat.  Again,  there  is 
stored  up,  if  we  may  so  speak,  in  a  mass  of  zinc,  a 
large  amount  of  latent  energy.  If  in  a  galvanic 
battery  that  zinc  dissolves  in  sulphuric  acid,  this 
energy  becomes  active,  and  reappears  in  a  current 
of  electricity.  Some  persons  do  not  like  the  term 
latent  energy,  and  speak  of  energy  which  is  not  in 
action  as  potential  or  possible.  In  like  manner 
they  speak  of  energy  in  action  as  dynamical  or 
actual.  But  terms  are  of  no  importance,  if  only  the 
ideas  which  they  express  are  fully  understood. 

Keeping  this  distinction  in  view,  we  shall  better 
understand  the  bearings  of  the  important  principles 
just  before  stated.  When  energy,  in  passing  from  one 
body  to  another,  changes  its  mode  of  manifestation, 
it  seldom  flows  wholly  into  one  channel,  and  almost 


330  RELIGION   AND    CHEMISTRY.  [LECT.  X. 

invariably  more  or  less  of  it  becomes  latent.  Thus 
— to  go  back  to  the  example  of  the  steam-engine  — 
of  the  energy  which  is  latent  in  the  coal  and  becomes 
active  in  the  form  of  heat  when  the  coal  burns,  not 
more  than  one  tenth  at  the  most  produces  any  useful 
mechanical  effect.  The  rest  becomes  again  latent  in 
changing  the  water  into  steam,  and  in  heating  and 
Energy  never  expanding  the  iron,  the  bricks,  the  water, 
and  the  air  in  contact  with  which  the  fuel 
burns.  All  this  heated  matter  represents  a  large 
amount  of  latent  energy.  It  is  in  the  condition  of 
the  wound-up  weight  of  a  clock,  and  as  it  cools,  this 
energy  is  distributed  to  surrounding  bodies.  Were 
it  now  possible,  at  a  given  instant  after  the  burning 
of  the  coal,  to  sum  up  all  the  energy,  both  active 
and  latent,  which  could  be  traced  directly  back  to 
the  burning  fuel,  it  would  be  found  that  not  the 
smallest  fraction  of  the  energy  originally  latent  in 
the  mass  of  coal  had  been  lost.  In  this  case,  of 
course,  accurate  experiments  are  out  of  the  ques- 
tion ;  but  wherever  it  has  been  possible  to  apply 
measurements,  it  has  been  found  that  the  principle 
here  illustrated  holds  true.  I  should  not  be  able 
to  make  the  methods  of  such  investigations  intel- 
ligible without  occupying  a  great  deal  of  time. 
Let  it  then  be  sufficient  to  state,  that  all  those  who 
have  most  carefully  studied  the  subject  have  ar- 
rived at  the  same  results.  There  is  therefore  every 
reason  to  believe  that  the  principle  we  have  been 
illustrating  is  universally  true.  Let  us  then  em- 
body it  in  a  definite  statement.  All  natural  phe- 


LECT.  X.]  AKGUMENT   FROM   GENERAL   PLAN.  331 

nomena  are  the  manifestation  of  the  same  omnipresent  en- 
ergy, which  is  transferred  from  one  portion  of  matter  to 
another  without  any  loss  of  power. 

But  if  the  principle  as  thus  stated  be  accepted,  we 
cannot  rest  here ;  for  it  involves  this  further  con- 
clusion, which,  however  marvellous,  must  be  true. 
The  sum  total  of  all  the  active  and  latent  energies  in  the 
universe  is  constant  and  invariable.  In  other  words, 
power  is  as  indestructible  as  matter.* 

This  grand  truth  is  generally  called  the  law  of 
conservation  of  energy,  and,  if  it  cannot  as  yet  be 
regarded  as  absolutely  verified,  there  can  conservation 
be  no  question  that  it  stands  on  a  better  ofener&y- 
basis  now  than  did  the  law  of  gravitation  one  hun- 
dred years  ago. 

But  how  can  I  give  you  any  conception  of  the 
sublimity  of  the  truth  which  this  formal  language 
implies,  but  which  no  language  is  adequate  to  ex- 
press ?  Even  poetry  in  the  highest  flights  of  fancy 
has  never  seen  such  a  vision  as  these  vistas  of  ac- 
tual realities  open  to  the  intellect  and  imagination 
of  man.  Keview  in  the  light  of  this  grand  gener- 
alization the  subsidiary  truth  which  from  time  to 
time  I  have  endeavored  to  illustrate  during  this 
course  of  Lectures, —  namely,  that  all  terrestrial  en- 
ergy comes  from  the  sun.  The  accumulated  power 
of  the  sun's  delicate  rays  produces,  as  we  before 
saw,  every  motion  and  every  change  which  takes 
place  on  the  surface  of  this  planet,  from  the  falling 

*   Many  philosophers  believe,  with  Newton,  that  matter  in  its  es- 
sence is  only  a  manifestation  of  power. 


332  RELIGION   AND    CHEMISTRY.  [LECT.  X. 

of  an  avalanche  to  the  crawling  of  a  worm.  But 
that  energy,  as  we  now  know,  is  not  exhausted  on 
the  earth.  To  use  the  eloquent  language  of  an- 
other :  "  Our  world  is  a  halting-place  where  this 
energy  is  conditioned.  Here  the  Proteus  works  his 
spells ;  the  selfsame  essence  takes  a  million  shapes 
and  hues,  and  finally  dissolves  into  its  primitive  and 
almost  formless  form.  The  sun  comes  to  us  as  heat ; 
he  quits  us  as  heat ;  and  between  his  entrance  and 
departure  the  multiform  powers  of  our  globe  appear. 
They  are  all  special  forms  of  solar  power,  —  the 
moulds  into  which  his  strength  is  temporarily 
poured,  in  passing  from  its  source  through  infini- 
tude."* 

Attempt  now  to  bring  together  in  imagination 
all  the  energies  acting  at  one  moment  on  the 
earth,  and  unite  them  in  one  tremendous  aggregate. 
Begin  with  the  moving  power  of  the  air,  the  hur- 
ricanes, the  tornadoes,  the  storms,  and  the  gentler 
winds  which  are  everywhere  at  work  from  the  Arc- 
tic to  the  Antarctic  Pole,  omitting  in  making  the 
estimate,  if  you  choose,  the  lightning  and  the  thun- 
der, which,  though  brilliant  and  noisy  demonstra- 
tions of  power,  would  hardly  increase  by  a  unit 
the  vast  sum.  Add  to  this  the  mechanical  power 
in  the  mighty  flow  of  waters,  the  ocean  currents, 
the  rivers,  the  cataracts,  the  glacier-streams,  and  the 
avalanches,  all  over  the  globe.  Bring  into  the  cal- 
culation the  forces  at  work  in  the  various  phases  of 

*  Professor  John  Tyndall,  in  the  work  already  quoted,  "  Heat  con- 
sidered as  a  Mode  of  Motion." 


LECT.  X.]  ARGUMENT   FROM   GENERAL   PLAN.  333 

animal  and  vegetable  life.  Eemember  the  confla- 
grations, the  furnaces,  the  fires,  and  the  other  man- 
ifestations of  the  terrible  energies  of  the  atmos- 
pheric oxygen,  whenever  it  is  aroused.  Do  not  even 
forget  the  comparatively  insignificant  power  which 
man  is  wielding  with  the  aid  of  powder  and  of  steam. 
Making  now  an  immense  allowance  for  what  you 
must  have  overlooked,  sum  this  all  up,  —  if  you  can 
without  bewilderment, —  and  what  part  is  it  of  the 
whole  ?  Why,  it  has  been  calculated  that  it  is  equal 
to  but  one  2,300,000,000th  of  the  force  which  the 
sun  is  every  moment  pouring  into  space.  And  what 
is  the  Sun  ?  A  small  star  in  the  infinitude  of  space, 
where  shine  Sirius  and  Arcturus,  Kegulus  and  Al- 
debaran,  Procyon  and  Capella,  with  unnumbered 
others,  all  shedding  forth  a  far  mightier  effluence 
than  our  feeble  star ;  yet  the  grand  total  of  the 
powers  streaming  from  all  the  suns  which  human 
eye  has  seen,  or  which  still  lie  undiscovered  in  the 
depths  of  space,  alone  represents  the  active  energy 
of  the  universe.  My  friends,  there  are  two  theories 
of  causation.  One  regards  this  energy  as  an  unin- 
telligent power.  The  other  sees  in  it  simply  the 
will  of  the  Eternal  Jehovah.  They  are  both  theo- 
ries. We  cannot  substantiate  either.  But  which 
do  you  think  is  the  more  probable  ?  Let  us  not 
pass  hasty  judgment,  but  soberly  weigh  all  the  tes- 
timony, and  base  our  decision  on  the  best  scientific 
evidence  we  can  obtain,  and  on  that  alone. 

Thus  far  in  our  discussion  we  have  been  dealing 
with  facts  and   principles  which  every  theory  of 


334  RELIGION  AND    CHEMISTRY.  [LECT.  X. 

causation  must  explain.  But  we  now  pass  into 
what  is  rather  the  region  of  speculation,  and  we  must 
step  more  cautiously.  I  have  used  thus  far  the 
terms  energy  and  transfer  of  energy ',  without  expecting 
tnat  you  would  attach  to  them  any  more  definite 
meaning  than  that  which  is  conveyed  by  the  words 
in  their  most  familiar  use.  Energy  is  a  definite 
thing,  which  is  as  palpable  to  our  senses  as  matter, 
and  which,  in  most  cases  at  least,  we  can  measure 
as  accurately.  Any  one  who  has  been  stunned  by 
a  blow  or  a  fall,  has  been  burnt  by  a  fire,  has  been 
dazzled  by  the  sun,  or  has  received  a  shock  of  elec- 
tricity, knows  well  enough  what  energy 

Energy  always 

appears  as  is  ;  and  the  doctrine  of  the  conservation 
of  energy  is  wholly  independent  of  any 
theory  which  men  may  entertain  in  regard  to  its  es- 
sence. For  this  reason,  I  have  aimed  to  present  the 
grand  doctrine  of  modern  science  entirely  free  from 
all  speculations  whatsoever;  but  now  that  we  are 
seeking  to  go  behind  the  external  phenomena,  it 
will  be  well  for  us  to  consider  very  briefly  a  theory 
which,  although  it  does  not  profess  to  explain  what 
energy  is  in  its  essence,  nevertheless  may  give  to 
the  mind  a  more  definite  conception  of  its  mode  of 
action.  The  theory,  it  is  true,  cannot  be  regarded 
as  fully  established ;  but  it  represents  the  undoubt- 
ed tendency  of  science,  and  the  materialists  would, 
of  all  others,  be  the  first  to  accept  it.  According  to 
the  modern  view,  all  energy  appears  as  motion,  and 
this  too  whether  it  be  manifested  in  mechanical 
work,  or  in  the  more  subtile  phenomena  of  sound, 


LKCT.  X.]  ARGUMENT   FROM   GENERAL   PLAN.  335 

light,  heat,  chemical  affinity,  electricity,  or  magne1> 
ism.  We  must,  however,  extend  our  idea  of  motion, 
and  not  limit  it,  as  is  usually  done,  to  the  motion 
of  masses  of  matter. 

Even  the  smallest  material  masses  perceptible  to 
our  senses  must  be  regarded  as  aggregates  of  still 
smaller  masses,  which  we  call  molecules  or  atoms. 
These  atoms,  moreover,  even  in  the  densest  bodies, 
cannot  be  in  contact,  and  we  must  picture  them  to 
our  imagination  each  as  a  tiny  world, 

0  J  7    Motion  of 

poised  in  space.  In  using  the  word  atom  atoms  to  be 
we  do  not  mean  to  imply  that  these 
particles  of  matter  are  mechanically  indivisible, 
as  its  derivation  would  indicate,  but  we  merely 
declare  that  they  are  so  many  separate  units  so 
far  as  our  science  is  concerned.  The  same  rela- 
tion which  the  worlds  bear  to  the  cosmos,  we  con- 
ceive that  these  atoms  bear  to  the  micro-cosmos 
which  every  mass  of  matter  represents,  and  it  is 
believed  that  the  motions  of  suns  and  systems  have 
their  miniature  in  the  motions  of  these  atoms.  The 
ether,  also,  of  which  I  spoke  in  the  second  Lecture 
as  filling  celestial  space,  is  supposed  to  pervade 
equally  the  atomic  spaces,  to  surround  each  atom 
with  a  highly  elastic  atmosphere,  and  to  be  the  me- 
dium by  which  motion  is  transmitted  throughout  a 
universe  which  includes  the  infinitesimal  as  well  as 
the  infinite.  Moreover,  we  conceive  that  the  mo- 
tion of  the  atom  is  the  exact  counterpart  of  the 
motion  of  a  world  or  of  the  motion  of  a  ball,  and 

that  all  motion  obeys  the  selfsame  laws.     As  when 
22 


336  RELIGION   AND    CHEMISTRY.  [LECT.  X. 

an  ivory  billiard-ball  strikes  another,  it  gives  up  the 
whole  or  a  part  of  its  motion  to  the  second  ball,  so 
we  believe  that  one  atom  may  transmit  motion  to 
another.  In  like  manner  as  an  impulse  is  transmit- 
ted through  a  long  line  of  billiard-balls,  and  the  last 
ball  only  appears  to  move,  so  also  we  conceive  that 
the  electrical  impulse  is  transmitted  from  atom  to 
atom  through  the  telegraph  wire,  and  produces  per- 
ceptible motion  only  when  transformed  into  magnet- 
ism at  the  end  of  a  thousand  miles.  Again,  motion 
may  be  transmitted  from  atoms  to  masses  of  mat- 
ter ;  for  although  the  impulse  imparted  by  a  single 
atom  may  be  as  nothing,  the  accumulated  effect  of 
millions  on  millions  of  these  impulses  may  be  im- 
mense. In  this  way,  we  conceive,  the  motions  of 
the  ether  particles  in  the  sunbeams  unite  to  pro- 
duce all  the  grand  phenomena  of  nature.  On  the 
other  hand,  the  motion  of  great  masses  may  be 
suddenly  resolved  into  the  motions  of  the  atoms 
composing  these  masses,  and  thus,  when  motion 
outwardly  appears  to  cease,  it  may  only  be  trans- 
ferred from  the  previously  moving  body  to  the 
atoms  within.  When  the  cannon-balls,  with  their 
immense  velocity,  strike  the  Ironsides,  and  fall  harm- 
lessly from  her  armor-plates,  the  particles  of  iron 
take  up  the  motion  of  the  ball,  and  indicate  by  a 
higher  temperature  that  the  energy  has  not  been 
lost. 

Understanding  then  the  term  motion  in  the  ex- 
tended sense  just  explained,  we  shall  comprehend 
more  clearly  the  theory  stated  above.  This  theory 


LECT.  X.]  ARGUMENT   PROM   GENERAL   PLAN.  337 

supposes  that  the  phenomena  of  sound,  light,  heat, 
and  electricity  are  produced  by  the  motions  of 
atoms,  in  the  same  way  that  the  grander  phenomena 
of  mechanics  and  astronomy  are  caused  by  the  mo- 
tion of  large  masses  of  matter.  The  transmission  of 
energy  is,  then,  the  direct  result  of  the  transmission 
of  motion,  and  the  conservation  of  energy  is  fully 
explained  by  the  well-known  law  of  inertia,  which 
the  motions  of  all  matter  necessarily  obey.  I  have 
not  time  to  enter  into  any  details  in  regard  to  the 
mode  of  motion  by  which  light,  heat,  and  all  this 
class  of  phenomena  are  produced,  other  than  those 
already  given  in  the  previous  Lectures  of  this 
course ;  but  I  take  great  pleasure  in  referring  my 
audience  to  the  work  of  Professor  Tyndall,  already 
frequently  quoted,  which  is  by  far  the  best  popular 
statement  of  the  subject  that  has  ever  been  made. 
Indeed,  great  differences  of  opinion  in  regard  to  the 
mode  of  the  atomic  motion  are  entertained  by  those 
who  accept  the  theory  in  its  general  statement,  and 
in  many  cases  we  can  form  no  conception  of  the  pecu- 
liar phase  which  the  motion  assumes.  It  is  sufficient 
for  my  purpose  if  I  have  been  able  to  make  clear 
the  general  principle,  and  I  will  only  add  a  ^ew  nu- 
merical results,  which  will  show  what  a  precise  form, 
the  theory  has  taken  in  the  minds  of  scientific  men. 
According  to  the  modern  theory,  when  we  heat 
a  body  we  merely  impart  to  its  atoms  a  greater  ve- 
locity of  motion.  Now,  according  to  the  experi- 
ments of  Professor  Joule,  when  we  raise  the  tem- 
perature of  a  pound  of  water  two  Fahrenheit  de- 


338  RELIGION   AND    CHEMISTRY.  [LECT.  X. 

grees,  we  distribute  among  the  atoms  of  the  liquid 
an  amount  of  motion  equal  to  that  acquired  by  a 
weight  of  two  pounds  in  falling  772  feet ;  and  a  sim- 
ple calculation  will  show  that  this  is  represented  by 
a  Minie  ball,  weighing  one  eighteenth  of 

Amount  of  .  °  ® 

the  atomic  a  pound,  moving  with  a  velocity  of  1,338 
feet  in  a  second.*  The  amount  of  motion, 
therefore,  which  is  imparted  to  the  particles  of  water 
in  an  ordinary  tea-kettle  during  the  process  of  boil- 
ing, must  be  in  the  aggregate  vastly  greater  than 
that  ever  acquired  by  any  projectile.  We  shall  ar- 
rive at  a  still  more  remarkable  result,  if  we  examine 
in  the  light  of  our  theory  the  process  of  chemical 
combination  by  which  water  is  formed.  In  this 
process  of  burning,  one  pound  of  hydrogen  gas 
combines  with  eight  pounds  of  oxygen  gas  to 
form  nine  pounds  of  water.  Although  the  dis- 
tances which  separate  the  atoms  of  the  two  gases 
before  combination  are  utterly  inappreciable  by  our 
senses,  yet,  in  passing  over  these  distances,  they  ac- 
quire a  velocity  which  causes  them  to  clash  together 
with  tremendous  energy,  and  in  the  collision  this 
form  of  atomic  motion  is  transmuted  into  that  other 
mode  of  motion  which  we  call  heat.  Incredible  as 
it  may  appear,  the  amount  of  motion  which  in  the 
act  of  combination  alone  is  thus  transmuted  into 
heat  corresponds  to  the  fall  of  a  ton  weight  down  a 
precipice  22,320  feet  high.  Such  illustrations  might 
be  multiplied  indefinitely;  but  you  will  see  from 

*  In  making  the  calculation,  it  must  be  remembered  that  the  amount 
of  motion  is  measured  by  the  square  of  the  velocity. 


LECT.  X.]  ARGUMENT   FROM   GENERAL   PLAN.  339 

these  how  purely  mechanical  the  idea  is  which  we 
associate  with  the  motion  of  an  atom,  and  you  must 
have  been  impressed  by  the  magnitude  of  the  en- 
ergy which  these  atomic  motions  represent.  "I 
have  seen,"  says  Professor  Tyndall,  "  the  wild  stone 
avalanches  of  the  Alps,  which  smoke  and  thunder 
down  the  declivities  with  a  vehemence  almost  suf- 
ficient to  stun  the  observer.  I  have  also  seen  snow- 
flakes  descending  so  softly  as  not  to  hurt  the  fragile 
spangles  of  which  they  were  composed  ;  yet  to  pro- 
duce from  aqueous  vapor  a  quantity  of  that  tender 
material  which  a  child  could  carry,  demands  an  ex- 
ertion of  energy  competent  to  gather  up  the  shat- 
tered blocks  of  the  largest  stone  avalanche  I  have 
ever  seen,  and  pitch  them  to  twice  the  height  from 
which  they  fell."  If  such,  then,  be  the  measure  of 
these  atomic  motions,  we  can  easily  conceive  how 
the  motion  of  the  cannon-ball  might  be  transferred 
to  the  particles  of  the  armor-plate  without  much 
apparent  result,  and  even  how  the  energy  of  a  world 
might  be  maintained  by  the  motion  of  the  atoms  in 
the  sunbeam. 

Accepting,  then,  this  new  theory  of  science,  and 
admitting  that  all  energy  is  manifested  in  motion, 
we  reduce  at  once  our  discussion  of  the  doctrine  of 
causation  to  this  simple  question,  —  What  is  the 
primary  cause  of  motion  ?  If  we  can  explain  the 
simplest  case  of  motion,  we  have  solved  the  prob- 
lem for  the  universe.  Take,  for  example,  a  boy's 
ball,  moving  through  the  air  under  the  impulse 
of  a  well-directed  blow.  Do  we  not  know  some- 


340  RELIGION   AND    CHEMISTRY.  [LECT.  X. 

thing  of  the  cause  of  that  motion  ?  Is  it  not  con- 
nected with  the  muscular  contraction  of  the  boy's 
arm,  produced  by  his  will  ?  Is  not  his  volition,  act- 
ing mysteriously  on  matter,  at  least  the  occasion  of 
the  motion  ?  It  is  perfectly  true  that  the  will  does 
not  create  the  motion.  The  ball  is  impelled  by  a 
portion  of  that  energy  in  nature  which  man  can 
neither  increase  nor  diminish.  But  still  the  boy's 
will  is  the  occasion  of  the  motion.  It  has  opened 
the  channel  through  which  the  energy  of  nature 
has  flowed  to  produce  the  specific  result  which  the 
boy  desired.  So,  in  a  thousand  other  ways,  man  is 
able  to  come  down,  as  it  were,  upon  nature,  and  to  in- 
troduce a  new  condition  into  the  chain  of  causation. 
Place  the  point  of  contact  as  far  back  as  you  please, 
theorize  about  the  subject  as  you  may,  the  fact  still 
remains  the  same.  Our  will  does  act  on  matter, 
and  does  act  to  produce  most  efficient  results. 
Here  is  energy  exerted  of  whose  cause  we  have 
the  consciousness  within  ourselves,  and,  if  the  anal- 
ogy is  worth  anything,  it  points  to  but  one  conclu- 
sion, —  namely,  that  motion  is  always  the  manifesta- 
tion of  will.  As  the  boy's  will  acted  on  that  atom 
of  matter,  which,  though  moved  perhaps  but  a 
hair's  breadth  from  its  position,  set  in  action  —  as 
if  by  the  touching  of  a  spring  —  the  train  of  natural 
causes  which  gave  motion  to  the  ball,  so  we  may 
suppose  that  the  Divine  will  acts  in  nature.  Ac- 
cording to  this  view,  the  energy  which  sustains  the 
universe  is  the  will  of  God,  and  the  law  of  conser- 
vation is  only  the  manifestation  of  His  immutable 


LECT.  X.]          LIMITS    OF   SCIENCE   AND   RELIGION.  341 

being,  —  "  the  same  yesterday,  and  to-day,  and  for- 
ever." 

We  do  not  say  that  this  theory  can  be  proved, 
for  certainty  here  is  out  of  the  question ;  but  we 
do  claim  that  it  is  based  on  the  only  analogy 
which  nature  affords,  that  it  is  a  legitimate  deduc- 
tion of  science,  and  that  it  is  perfectly  consistent 
with  Christian  faith.  On  a  subject  where  science 
can  only  grope,  the  wildest  theories  are  possible ; 
but  these  should  not  trouble  a  well-balanced  mind, 
so  long  as  there  exists  an  equally  probable  theory 
which  can  be  reconciled  with  the  purest  faith.  It 
has  been  my  aim  in  this  Lecture  to  show,  not  only 
that  such  a  theory  is  tenable,  but  also  that  the 
Christian  theory  of  causation  is  the  most  probable 
theory  of  science ;  and  my  earnest  hope  is,  that,  for 
some  minds  at  least,  the  considerations  I  have  of- 
fered will  help  to  reconcile  the  apparent  conflict 
between  science  and  religion,  which  materialism  is 
ever  striving  to  foment.  Allow  me  to  add,  in  con- 
cluding, one  or  two  other  suggestions  which  may  be 
of  value  in  the  same  direction. 

I  cannot  but  believe   that  the   appearance  of 
clashing   between   science  and   religion  would  be 
wholly  avoided,  if  the  teachers  both  of  Necegsary 
God's  unwritten  and  of  His  written  word  limitations  of 

_  _  -i  j/i  scientific  and 

would    pay   more   regard    to   the   neces-  religious 
sary  limitations  of  scientific  and  religious  thought> 
thought.     On  subjects  where  the  methods  of  acquir- 
ing knowledge   are   so  utterly  unlike,  where  the 
relations  of  the  knowledge  to  the  human  under- 


342  RELIGION   AND    CHEMISTRY.  [LECT.  X. 

standing  are  so  different  when  gained,  it  is  in 
vain  to  expect  literal  accordance.  Science,  both 
in  its  methods  and  its  results,  addresses  the  under- 
standing exclusively ;  Christianity  appeals  chiefly 
to  the  heart.  Science  aims  to  instruct ;  Chris- 
tianity aims  to  persuade.  Science  is  attained  by 
study,  and  is  possible  only  for  the  few ;  Chris- 
tianity is  a  free  gift  from  God  to  all  men  who  will 
receive  His  Son.  The  results  of  science  are  fully 
comprehended,  and  can  be  expressed  in  definite 
terms  •  the  truths  of  Christianity  stand  on  a  level 
above  man's  intellect,  and  can  only  be  shadowed 
forth  in  types  and  symbols.  The  forms  of  science 
are  constantly  changing ;  the  types  and  symbols  of 
Christianity  are  permanent.  Lastly,  while  the  lan- 
guage of  science  may  be  so  varied  from  time  to 
time  as  to  express  accurately  the  current  ideas, 
Christianity  necessarily  retains  the  forms  through 
which  it  was  first  revealed.  Under  such  conditions 
how  can  it  be  expected  that  the  language  of  rev- 
elation should  agree  with  the  letter  of  science  ? 
You  might  as  reasonably  find  fault  with  nature  be- 
cause its  crystals  are  not  perfect,  as  criticise  the 
Bible  because  its  language,  although  embodying 
divine  truth,  is  not  free  from  the  necessary  limita- 
tions and  imperfections  of  the  human  medium  of 
thought. 

I  have  not  time  to  develop  the  ideas  here  sug- 
gested ;  but  the  bearing  of  the  facts  is  obvious,  and 
practical  con-  they  lead  to  important  practical  conclu- 
giong  jn  the  firgt  jace  the  should 


LECT.  X.]          LIMITS    OF   SCIENCE   AND    RELIGION.  343 

teach  men  of  science  to  honor  and  reverence  the 
forms  of  religion.  They  are  the  types  and  symbols 
of  a  higher  truth  than  any  Science  can  teach.  Let 
Science  vindicate  her  own  methods,  and  allow  no 
interference  within  her  proper  sphere;  but  unless 
she  learn  that  there  are  other  sources  of  knowl- 
edge than  material  nature,  and  other  channels  of 
truth  than  the  intellect,  her  own  philosophy  will  be 
confounded,  and  her  light  will  go  out  in  darkness. 
On  the  other  hand,  it  is  equally  the  duty  of  the 
ministers  of  religion  to  honor  and  respect  the  meth- 
ods of  science.  They  have  been  ordained  by  God, 
and  through  these  processes  of  thought  He  is  con- 
stantly revealing  eternal  truths  to  the  mind  of 
man.  Insist  as  strongly  as  you  please  that  Science 
should  be  allowed  no  voice  in  matters  of  faith. 
Scrutinize  as  closely  as  you  can  every  step  of  her 
logic ;  but  so  long  as  she  keeps  within  her  legiti- 
mate province,  allow  her  the  largest  liberty,  and 
extend  to  her  the  most  generous  encouragement. 
"Watch  sharply  her  results,  and  expose  her  fallacies 
wherever  you  can  find  them;  but,  if  your  judg- 
ment condemns,  let  it  be  on  scientific  grounds,  and 
not  by  any  arbitrary  standard  of  your  own.  Above 
all,  even  if  you  think  your  most  cherished  opinions 
are  in  danger,  do  not  withdraw  your  fellowship 
hastily,  or  be  betrayed  into  undiscriminating  cen- 
sure. Science  is  paramount  within  her  own  prov- 
ince. Do  everything  in  your  power  to  consecrate 
her  aims  and  sanctify  her  spirit,  but  do  not  attempt 
to  control  her  investigations  or  restrict  her  free 


344  RELIGION   AND    CHEMISTRY.  [LECT.  X. 

thought.  Await  God's  time.  If  science  is  wrong, 
she  will  sooner  or  later  correct  her  error.  If  she  is 
right,  God  is  on  her  side,  and  you  would  find  your- 
self fighting  against  the  great  Jehovah. 

Again,  a  proper  appreciation  of  the  necessary 
limits  of  scientific  and  religious  thought  should  lead 
all  men  to  reverence  the  Word  of  God  as  it  has 
been  handed  down  to  us  through  history.  In  view 
of  the  facts  already  intimated,  I  cannot  look  with 
favor  on  any  attempts  at  Biblical  criticism  which 
aim  to  square  the  language  of  Scripture  by  the 
results  of  modern  science.  They  leave  a  most  un- 
pleasant impression  on  my  mind.  I  believe  the 
Bible  inspired,  from  the  grand  epic  of  creation, 
with  which  it  opens,  to  the  glorious  vision  of  the 
New  Jerusalem  at  its  close.  I  feel  that  its  very 
words  are  sacred,  and  if  you  are  so  ready  to  accom- 
modate any  part  of  them  to  the  shifting  phases  of 
science,  what  certainty  can  I  have  in  regard  to  the 
whole  ?  The  Bible  is  no  text-book  of  science,  and 
the  attempt  to  impose  an  equivocal  or  mysterious 
meaning  on  its  simple  and  obvious  statements  de- 
grades and  dishonors  it  in  the  minds  of  devout  men. 
The  methods  by  which  its  truths  are  expressed  may 
be  at  times  rough  and  uncouth ;  but  they  are  the 
methods  chosen  by  God,  consecrated  by  the  blood 
of  martyrs,  and  hallowed  by  the  tears  of  saints ;  and 
they  have  therefore  a  power  which  no  other  lan- 
guage could  have.  Break  not  the  mould  in  which 
the  forms  of  faith  have  been  cast,  before  they  have 
become  firm  and  hard,  lest  the  precious  metal 


LKCT.X.]          LIMITS    OF   SCIENCE   AND   RELIGION.  345 

should  itself  be  lost.  Finally,  leave  religion  and 
science  to  their  respective  methods,  and  encourage 
both  alike  in  their  noble  calling.  Let  science,  by 
cultivating  man's  intellect,  elevate  him  to  nobler 
and  more  spiritual  views  of  God's  wisdom  and 
power.  Let  religion,  by  purifying  man's  heart, 
open  to  him  clearer  visions  of  God's  purity  and 
love ;  and,  at  last,  when  this  material  shall  have 
vanished,  and  when  the  waters  of  controversy  shall 
have  ceased  to  roll,  the  heart  and  the  intellect, 
made  one  and  washed  clean  in  the  blood  of  the 
Lamb,  shall  unite  in  the  song  of  the  angels  around 
the  throne,  saying,  "Blessing,  and  glory,  and  wis- 
"  dom,  and  thanksgiving,  and  honor,  and  power, 
a  and  might,  be  unto  our  God  for  ever  and  ever." 

But  while  insisting  upon  the  necessary  limita- 
tions of  scientific  and  religious  thought,  I  must  not 
forget  .that  all  such  considerations  bear  Limitg  of  natu. 
with  peculiar  force  upon  the  questions  raltheol°gy- 
which  it  has  been  my  privilege  to  discuss  in  this 
course  of  Lectures.  Therefore,  although  I  have 
most  carefully  endeavored  to  guard  my  argument 
from  the  slightest  exaggeration,  I  should  not  feel 
justified  in  concluding  without  distinctly  stating 
how  far  in  my  opinion  the  argument  of  natural 
theology  may  be  safely  carried,  and  to  what  extent 
unaided  science  may  be  said  really  to  prove  the 
fundamental  truths  of  Christianity. 

In  the  first  place,  then,  I  believe  that  the  exist- 
ence of  an  intelligent  author  of  nature,  infinite  in 
wisdom  and  absolute  in  power,  may  be  proved 


346  RELIGION   AND    CHEMISTRY.  [LECT.  X. 

from  the  phenomena  of  the  material  world  with  as 
much  certainty  as  can  any  general  truth  of  science. 
In  the  second  place,  I  am  of  opinion  that  the  facts 
of  nature  also  prove  —  although  the  arguments 
adduced  may  be  less  convincing  —  that  the  author 
of  nature  is  a  personal  being,  and  the  one  only 
and  true  God  revealed  to  us  in  the  Bible.  Lastly, 
I  think  that  the  relations  of  the  human  mind  to 
the  material  world,  viewed  in  the  light  of  modern 
science,  give  us  strong  reason  to  believe,  on  scien- 
tific grounds  alone,  that  the  universe  is  still  sus- 
tained, in  all  its  parts,  by  the  same  omnipotent  and 
omniscient  Will  which  first  called  it  into  being.  It 
may  be  that  God  intrusts  the  execution  of  His  will 
to  subsidiary  intelligences,  and  such  a  belief  is  per- 
fectly consistent  with  the  above  conclusions.  But 
nature  throws  no  light  upon  the  subject,  and 
therefore  I  have  not  discussed  this  question.  If, 
however,  such  agents  exist,  the  facts  of  nature  just 
referred  to  would  tend  to  show  that  they  must 
be  intelligent  causes,  and  subject  to  Him  who  is 
all  in  all. 

To  the  extent  I  have  indicated  I  regard  the  argu- 
ment of  natural  theology  as  logically  valid.  More- 
over, I  am  persuaded  that  science  confirms  and 
illustrates  the  priceless  truth  which  Christ  came 
on  earth  to  reveal ;  but  I  do  not  believe  that  the 
unaided  intellect  of  man  could  ever  have  attained 
to  certainty  in  regard  to  even  the  least  of  these 
truths,  independently  of  revelation.  Nevertheless, 
as  I  stated  in  my  introductory  Lecture,  I  feel  that 


LECT.  X.]          LIMITS    OF   SCIENCE   AND    RELIGION.  347 

the  best  service  which  science  can  render  to  re- 
ligion is  in  the  way  of  confirmation  and  illustra- 
tion, rather  than  in  that  of  absolute  proof,  and  for 
this  reason  I  have  preferred  to  discuss  my  subject 
chiefly  from  that  point  of  view. 

The  subject,  as  prescribed  by  the  founder  of  these 
Lectures,  is  "  The  power,  wisdom,  and  goodness  of 
God  as  manifested  in  His  works,"  and  to  this  form 
of  statement,  if  interpreted  in  the  sense  just  indi- 
cated, I  have  nothing  to  object.  I  do  not  believe, 
however,  in  any  sense,  that  nature  proves  the  good- 
ness of  God.  When  the  heart  has  been 

Nature  does 

once  touched  by  the  love  of  God,  as  not  prove  God's 
manifested  on  Calvary,  the  tokens  of 
God's  goodness  are  seen  everywhere  :  but  before 
this,  nature,  to  one  who  has  seen  its  terrors  and 
felt  its  power,  looks  dark  indeed ;  and  the  pre- 
tence that  the  material  universe,  unexplained  by 
revelation,  manifests  a  God  of  unmixed  beneficence, 
not  only  does  harm  to  religion,  but  places  science 
in  a  false  light.  The  most  superficial  observation 
shows  that  this  is  not  true.  Lightning  and  tem- 
pest, plague,  pestilence,  and  famine,  with  all  their 
awful  accompaniments,  are  no  less  facts  of  nature 
than  the  golden  sunset,  the  summer's  breeze,  and 
the  ripening  harvest ;  and  who  does  not  "  know 
u  that  the  whole  creation  groaneth  and  travaileth  in 
"  pain  together  until  now"  ?  It  does  not  change  the 
terrible  fact  to  say  that  nature  has  been  disordered 
by  man's  sin ;  for  sin  is  itself  the  greatest  evil  in 
the  world,  and  its  ghastly  forms  meet  us  at  every 


348  RELIGION   AND    CHEMISTRY.  [LECT.  X. 

step.  So  prominent,  indeed,  is  the  evil  in  nature, 
and  so  insidiously  and  mysteriously  does  it  pervade 
the  whole  system,  that  an  argument  to  prove  the 
malignity  of  God  could  be  made  to  appear  quite  as 
plausible  as  the  arguments  which  are  frequently 
urged  to  prove  His  pure  beneficence ;  and  wherever 
the  unaided  human  intellect  has  attempted  to  make 
to  itself  a  beneficent  God,  it  has  always  made  a 
malignant  Deity  as  well.  Nature  manifests  God's 
wrath  no  less  than  His  love,  and  it  is  a  false  and 
sickly  philosophy  which  attempts  to  keep  the  awful 
fact  out  of  sight.  God  is  our  Father ;  but  nature 
could  not  teach  it,  and  "the  Word  was  made  flesh" 
to  declare  it.  God  is  love ;  but  nature  could  not 
prove  it,  and  the  Lamb  was  "slain  from  the  founda- 
tion of  the  world"  to  attest  it.  Nature  is  but  a 
part  of  God's  system,  and  not  until  the  natural  and 
the  supernatural  shall  be  made  one  will  the  mys- 
tery of  evil  be  solved. 


THE  .  END. 


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20m-l,'22 


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UNIVERSITY  OF  CALIFORNIA  LIBRARY 


